University of Florida Thesis Or Dissertation Formatting

AMERICAN COCKROACH SURVIVAL AND CONTROL IN WOOD VOIDS

DALLIN ASHBY

A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE

UNIVERSITY OF FLORIDA

2017

To my wife and children

ACKNOWLEDGMENTS

I thank Dr. Philip Koehler for his persistent support and ideas that helped to shape my research. I thank Dr. Roberto Pereira for his assistance in helping me develop the analytical and computational aspects of my findings, and the direction he offered in formatting the text within my thesis. I thank Dr. Rebecca Baldwin for being a source of encouragement and empathy throughout the process, as well as providing sound scientific viewpoints regarding the creation of this thesis.

I thank my wife for her constant support and loving friendship despite my many days away from home. Her patience and understanding were invaluable to the process of completing this thesis.

TABLE OF CONTENTS

page

ACKNOWLEDGMENTS ...... 4

LIST OF TABLES ...... 7

LIST OF FIGURES ...... 8

ABSTRACT ...... 10

CHAPTER

1 INTRODUCTION ...... 12

2 LITERATURE REVIEW ...... 15

Origin ...... 15 Distribution ...... 16 Biology ...... 17 Importance ...... 21 Control ...... 22

3 LONGEVITY OF STARVED, WATER-DEPRIVED AMERICAN COCKROACHES IN WOOD HARBORAGES AT VARIOUS WOOD MOISTURE LEVELS ...... 29

Materials and Methods...... 30 Insects ...... 30 Harborages ...... 31 Bioassay ...... 31 Analysis ...... 33 Results ...... 33 Discussion ...... 35

4 EFFICACY OF POSSIBLE PRECONSTRUCTION WALL VOID TREATMENTS AGAINST AMERICAN COCKROACHES, SILVERFISH AND CARPENTER ANTS ...... 49

Materials and Methods...... 50 Insects ...... 50 Wood Blocks ...... 52 Treatments ...... 53 Bioassays ...... 54 Analysis ...... 55 Results ...... 56

Discussion ...... 58

5 CONCLUSIONS ...... 68

LIST OF REFERENCES ...... 72

BIOGRAPHICAL SKETCH ...... 82

LIST OF TABLES

Table page

3-1 Days to mortality for starved and water-deprived 1st-instar nymphs, 3rd-4th- instar nymphs and adult American cockroaches at 0-30% wood moisture and resulting relative humidities...... 43

LIST OF FIGURES

Figure page

3-1 Wood block harborage with acetate paper circle stapled over the top and a 1st-instar nymph inside. Four holes were used as wells for increasing wood moisture...... 44

3-2 Fecal pellets of an adult American cockroach, derived from standard cockroach diet (left) and white pine (collected from the wood harborage in which it lived while deprived of food and water...... 44

3-3 Mean longevity in days of 1st-instar nymphs, 3rd-4th-instar nymphs and adults of American cockroaches living in wood harborages at different moisture levels...... 45

3-4 Longevity of 1st-instar nymphs, 3rd-4th-instar nymphs, and adults of the American cockroach while starved and water-deprived in wood harborages of various wood moisture levels...... 46

3-5 Linear regressions of fecal pellet (composed of wood) and body weights of starved and water-deprived 3rd-4th-instar nymphs and adults of the American cockroach...... 48

3-6 Mean weight of wood-composed fecal pellets (feces weight at mortality/days lived) produced by starved, water-deprived male (M) and female (F) American cockroaches...... 48

4-1 Experimental unit used to test the efficacy of insecticide treatments on wood against cockroaches, silverfish and carpenter ants. A 60-mL deli cup was secured to the treated surface of white pine with elastic bands...... 62

4-2 Mortality rates of 3rd-4th-instar American cockroaches, silverfish and Florida carpenter ants combined, after seven days of exposure to seven pesticide treatments on wood...... 63

4-3 Mortality rates of 3rd-4th-instar American cockroaches after 24 hours of exposure to CimeXa™, Totality™, or a combination of Totality™ and CimeXa™ , with treatments having been variably aged...... 64

4-4 Mortality rates of 3rd-4th-instar American cockroaches after 7 days of exposure to CimeXa™ alone, Arilon® , Phantom® , or TalstarOne™ after aging...... 65

4-5 Mortality rates of silverfish after 7 days of exposure to CimeXa™ alone, CimeXa™ mixed with: Arilon®, Phantom®, or TalstarOne™, one day or accelerated aging of 1 year, 2 years or 5 years post treatment...... 66

4-6 Mortality rates of Florida carpenter ants after 7 days of exposure to CimeXa™ alone, CimeXa™ mixed with: Arilon®, Phantom®, or TalstarOne™, after variable aging...... 67

Abstract of Thesis Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Master of Science

AMERICAN COCKROACH SURVIVAL AND CONTROL IN WOOD VOIDS

Dallin Ashby

August 2017

Chair: Philip Koehler Cochair: Rebecca Baldwin Major: Entomology and Nematology

This is the first study to measure the longevity of starved, water-deprived

American cockroaches in wood harborages and specifically measure the longevity of

1st-instar nymphs of the species. Longevity was correlated with wood moisture content and resulting relative humidity levels. Those cockroaches in blocks at higher wood moisture levels survived longest. Both 3rd-4th-instar nymphs and adults consumed wood in which they were kept during this research. Consumption of wood did not allow these otherwise starving cockroaches to thrive; therefore, though wood-feeding activity was prolonged by high wood moisture in wood voids, feeding did not sustain individuals.

Maintenance of wall void humidity to control insects is not always feasible. Wood treated with CimeXa™ can kill three insect species known to infest wall voids though mortality rates never exceeded 80% after seven days of exposure in two of three species. Phantom®, TalstarOne™ and Totality™ alone lost efficacy over time, but when mixed with CimeXa™, their efficacy was maintained over the accelerated aging equivalent of five years, never dropping significantly below 100% mortality. Of the toxicants tested in this research, only Totality™ is currently labeled for application to wood framing. The addition of CimeXa™ to preconstruction treatments with Totality™

would save resources, as post construction wall void treatments should be unnecessary within the first five years. Though the other pesticides tested are not currently labeled for use as termiticides applied to wood framing, tank mixing with CimeXa™ for improved longevity is plausible for at least Phantom® and TalstarOne™.

CHAPTER 1 INTRODUCTION

American cockroaches (Periplaneta americana Linnaeus) are one of the most common cockroaches in the United States (Tarshis 1959). They can be found inside and outside of homes (Hagenbuch et al, 1988), including inside wall voids and attics

(Owens and Bennett 1982, Appel 1997). Wall voids are especially ideal for American cockroach harborage when water damage is present or moisture problems exist

(Benson 1987). This is due to the need these cockroaches have for readily accessible water as well as moderate to high humidity (Willis and Lewis 1957).

Besides cockroaches, there are several insects known to inhabit wall voids.

Florida carpenter ants (Camponotus floridanus) can infest wall voids (Fowler 1986) and silverfish (Lepisma saccharina) often spend part or all of their lives in hidden areas like wall voids, thus making a treatment to such voids with long-lasting residual insecticides requisite (Ebeling et al. 1969).

Cockroaches and termites have classically been viewed as the most important structure-infesting insects in the in the United States (Ebeling 1978). Homes are routinely treated against termites during the construction process, but not so for cockroaches or other structure-infesting pests. Ebeling et al. (1969) argue that treating inside of walls against cockroaches and other insects during construction will help mitigate needed treatments to living spaces over time. One of the steps that regularly occurs in preconstruction treatments against termites is spraying the lower portions of wood frame members with boric acid solution, which absorbs into the wood surface

(Grace and Yamamoto 1994). Recently, a new bifenthrin product by FMC, Totality™, has also been approved for use as a termiticide on wood frame members during home

construction (FMC 2017). Like the boric acid treatments, Totality™ absorbs into the wood. Bifenthrin is also used as a broad-spectrum insecticide in many chemical formulations, with myriad insects listed as target organisms (Zaim et al 2000, Anon

2002, Hougard et al 2002). In theory, the application of a desiccant dust tank-mixed with

Totality™ to the framing timbers of a house in lieu of the standard boric acid spray could save time and money in the long run by providing protection from more than just termites in a single application. Liquid sprays may be absorbed into the substrate upon which they were applied, such as wood, which could render the pesticide residues inaccessible to target pests crawling on the surface (Ebeling et al. 1969). Application of a tank-mixed toxicant and desiccant dust as a single treatment against both termites and cockroaches could be advantageous in that a fraction of the toxicant may remain on the surface of the wood with the desiccant dust while the rest penetrates the wood’s surface.

Besides being the most important structural pests, termites and cockroaches share other characteristics in common, including a relatively thin wax layer (Ebeling and

Wagner 1959) similar digestive systems (Watanabe and Tokuda 2010), the consumption of cellulose (Wharton et al. 1965a, Gijzen et al. 1994), and engaging in coprophagy (Cruden and Markovetz 1984). Recent molecular phylogenic work puts these two groups of insects into a single order, Blattodea (Inward 2007). Whereas wood consumption by termites is common knowledge, only a few cockroaches are known to regularly feed on cellulosic material (Schrivener et al. 1989, Slaytor 1992, Watanabe and Tokuda 2010), with the genus Cryptocercus being a well-known example (Inward et al. 2007). American cockroaches prefer to eat starches and sugars to cellulose (Bell

and Adiyodi 1981), though they have been documented to eat paper (Wharton et al.

1965, Gijzen et al. 1994) with the nutritional value of the cellulose consumed being under debate (Gijzen et al. 1994, Watanabe and Tokuda 2010).

While similarities exist between them, American cockroaches and termites exhibit very different life histories. With their propensity to associate with filth (Asahina 1961,

Bell and Adiyodi 1981), American cockroaches are known to be carriers of several disease-causing bacteria and other pathogens (Fathpour 2003, Pai et al. 2005, Vahabi et al 2011). With American and other cockroach species living and breeding in wall voids, it is important to understand their control within these harborages.

The habits of domiciliary cockroaches in buildings are similar enough that one representative species can be used to discuss other domiciliary cockroaches (Ebeling

1978). The proceeding research was conducted using American cockroaches as a model for domiciliary cockroaches in general, partly because of the broad knowledge already available on the species. Two studies were conducted to help gain a better understanding of American cockroach survival in wall voids, and what measures can be taken to prevent wall void infestations, including: a) determining the longevity of starved, water-deprived American cockroaches in wood harborages at various wood moisture levels (Chapter 3), and b) assess the efficacy of possible preconstruction wall void treatments against American cockroaches, silverfish and Florida carpenter ants over accelerated aging of up to five years (Chapter 4).

CHAPTER 2 LITERATURE REVIEW

Origin

The radiation of insects during the Carboniferous was due, in part, to the advent of flight and the evolution of wings that could be folded back over the abdomen for protection while at rest. Cockroaches are an example of the success of this design. In the fossil record of the Upper Carboniferous Period (359-299 Mya), cockroaches have been the most ubiquitous insects found, comprising about 80% of insect fossil specimens (Carpenter and Burnham 1985). Modern cockroaches date back to the Early

Cretaceous period (120 Mya). Early cockroaches are readily distinguished from more modern species by the presence of an ovipositor on the females. Modern cockroaches lack these ovipositors (Carpenter and Burnham 1985, Legendre et al. 2015).

The morphological characteristics used to identify cockroaches are usually not preserved in fossils. There are only about four or five families that fossil cockroaches are commonly placed in because they are so difficult to identify. Cockroach fossils of the

Upper Carboniferous period are most often found in coal shale, indicating that they probably lived in swamps and other wet environments (Carpenter and Burnham 1985), which probably lent to their rapid decay and lack of preservation.

There are no known prehistoric records of cockroaches, which means that we are uncertain of when they started associating with man-made structures or dwellings.

Individual cockroach species becoming synanthropic over evolutionary time is convergent, meaning that the several extant domestic species became so without a common synanthropic ancestor (Grandcolas 1998).

The cockroach genus Cryptocercus is an evolutionary intermediate to the termites (Lo et al. 2000) and is considered to be a sister clade (Inward et al. 2007).

Intracellular symbiosis is ubiquitous in cockroaches but only one species of termite shares this. It is apparent that cockroaches and termites shared a common ancestor that originally had these intracellular symbionts (Bandi et al. 1995). Early work on the degradation of cellulose in American cockroaches (Periplaneta americana Linnaeus) showed that there might be endosymbionts responsible for cellulose degradation

(Bignell 1976), which would imply the ability of these roaches to use wood as a food source, much like the termites. More recent work has shown that this is not the case, but rather, hindgut bacteria and protozoa do not play a role in carbohydrate digestion in either the American cockroach or a decaying wood-eating cockroach (Panesthia cribrata) (Scrivener et al. 1998). In fact, Cryptocercus is the only cockroach lineage to share the same suite of oxymonadid and hypermastigid endosymbionts with termites

(Termitidae) (Klass et al. 2008).

Distribution

American cockroaches belong to the family Blattidae, within the order Blattodea

(Triplehorn and Johnson 2005). There are over 20 species within the genus Periplaneta worldwide. Four of these, P. americana, P. australasiae (Fabricus), P. brunnea

(Burmeister) and P. fuliginosa (Serville) are found in the United States though none of these are native to the North American continent. Periplaneta americana originated in tropical Africa where they can still be found inside and outside of dwellings. They are likely to have arrived in the Americas by 1625 or earlier (Bell and Adiyodi 1981).

American cockroaches have also been found indoors and outdoors in Thailand

(Sriwichai, et al. 2002) and Japan (Asahina 1961). They are currently cosmopolitan in distribution, having been spread by world commerce (Bell and Adiyodi 1981).

Today, most cockroaches are not synanthropic, or ‘domestic’. About a dozen roaches are currently considered peridomestic, causing serious problems because of their propensity to breed outdoors but periodically make their way into inhabited structures (Hagenbuch et al 1988). As examples, Fleet et al, (1978) listed several peridomestic cockroaches they found around a Texas home: P. fuliginosa, Parcoblatta fulvescens (Saussure and Zehntner), Parcoblatta pennsylvanica (DeGeer),

Pseudomops septentrionalis Hebard (Blattellidae), P. americana, Picnoscelus surinamensis (L.) (Blaberidae). Unlike the domestic cockroach Blattella germanica

(Linnaeus), these cockroaches do not rely on people, their dwellings and products for survival.

Biology

American cockroaches are the most common cockroaches in city sewer systems worldwide (Jones 2008). Population growth pressure of American cockroaches in sewer systems may lead to migration indoors, especially where old or broken plumbing allows for access. This is especially true in warmer months when populations increase the most (Haines and Palmer 1953). In summer time, they can be found in alleyways and yards next to infested buildings (Gould and Deay 1938). In Hawaii, they have been found in great numbers at night on thorn-producing Tribulus blossoms (Bryan 1926).

Similarly, Seelinger (1984) found them feeding on fallen flowers of coconut palms and hibiscus in Jamaica. Gould and Deay (1940) also reported finding American cockroaches in palm trees and decaying maple trees. They can sometimes be found in caves as well (Bell and Adiyodi 1981). American cockroaches do not share the same

local distributions as P. fuliginosa, P. brunnea, or P. australasiae (Haines and Palmer

1955, Brenner 1988, Seelinger 1984). For example, P. americana tend to occupy lower strata than P. australasiae in a shared environment outdoors (Seelinger 1984).

However, P. americana will readily aggregate when presented with odors of other species of cockroach, unlike most species which are repelled by the scents of non- conspecific individuals (Leoncini and Rivault 2005).

In many countries around the world, populations of American cockroaches can build up in homes when food and water are available. However, they are at least as well adapted for living outside as inside human dwellings (Seelinger 1984). They only become resident pests under conducive conditions. People in the US tend to have low tolerance thresholds for any cockroaches (Schal and Hamilton 1990) such that even cockroaches that only occasionally find their way into buildings from the outside are considered pests.

Indoors, American cockroaches can often be found in restaurants, grocery stores, food-processing facilities, warehouses (Bell and Adiyodi 1981), basements and cellars (Gould and Deay 1938). Established populations can also be found in wall and ceiling voids (Appel 1997, Owens and Bennett 1982), especially those with water damage (Benson 1987).

Inasmuch as American cockroaches require relatively high humidity and ready access to water, females tend to deposit their eggs in moist and secluded areas (Bell and Adiyodi 1981). Their eggs are contained within an egg capsule, or ootheca, which provides protection from desiccation and predation until the eggs hatch. Each ootheca usually contains about 14 eggs, though 16 eggs is the highest number any ootheca can

contain. After an ootheca is deposited, it may take about 55 days for the eggs to hatch.

An adult female may produce upwards of 90 oothecae in her lifetime (Gould and Deay

1938). Nymphs that successfully emerge from the ootheca undergo up to 13 molts before reaching adulthood, though this number is variable. The first molt usually occurs within about a month of emergence from the ootheca. The nymphal stage is normally completed in between 285 and 616 days, depending on abiotic factors such as temperature and humidity. The adult stage may last anywhere from 125 to 1212 days

(Gould and Deay 1940).

Several factors are known to affect longevity of American cockroaches including relative humidity (Smith et al. 1999), amount of life spent in captivity (Rau 1940), excessive light (Solomon et al. 1977), temperature (Wharton et al. 1965) and access to food and water (Willis and Lewis 1957). For the present study, it is important to note that adult American cockroaches may live more than twice as long when they have been kept captive their entire lives as compared to those adults that were captured as late instar nymphs (Rau 1940).

American cockroaches are opportunistic feeders, eating both plant and animal- based products (Bell and Adiyodi 1981). Nigam (1933) reported these roaches feeding on such things as bread, fruit, paper, leather and hair. Where the following items are available, they may also eat prepared fish, bean cake, rice, putrid sake, oil paper, peanuts, starchy paste, crepe de Chine and other cloth, and dead insects (Takahashi

1924). Also, of the carbohydrates they ingest, American cockroaches prefer consuming starches and sucrose to cellulose (Scrivener et al. 1998).

Cockroaches can eat food without water though much less food is consumed when they are deprived of water. When American cockroaches are dehydrated, the rectum reabsorbs water such that concentrated fecal pellets are produced. In order to recycle needed water, the rectum fills, filters and then refills with waste. The process of reabsorption in the gut is able to take place against an increasing osmotic gradient (Wall

1969). When cockroaches are starved, they experience an increase in total water content in relation to body weight. Additionally, blood volume is much lower in starved cockroaches than non-starved cockroaches (Wharton et al. 1965).

Though food and water are needed to survive, water alone allows for greater cockroach longevity than does food alone or complete deprivation of food and water.

Also, bigger cockroach species tend to live longer than smaller cockroach species when subjected to water deprivation. American cockroach adult females are able to survive 3 months on water alone in 36 to 40% relative humidity in glass containers. To compare, the longevity of adult American cockroaches living at 36% relative humidity but without food or water is about 28 days for males and 41 days for females. (Willis and Lewis

1957).

Relative humidity is important for cockroach survival not only under conditions of food and/or water deprivation (Dambach and Goehln 1998), but in normal conditions, too. Air movement is repellent to American cockroaches because moving air can wick away moisture from their bodies faster than still air. As the velocity of air increases, the rate of desiccation of an exposed cockroach will also increase (Oswalt et al. 1997).

Desiccant dusts are also repellent to cockroaches for the same reason. Cockroaches can learn to avoid insecticidal dusts, including desiccant dusts (Ebeling et al. 1967).

Cuticular permeability has a positive relationship with change in relative humidity.

Increasing the relative humidity around a cockroach causes its cuticle to become more permeable and thus more susceptible to dehydration. The amount of water in cockroach feces increases with an increase in relative humidity (Appel and Rust 1984) thus highlighting important coping mechanisms cockroaches are able to employ in order to avoid desiccation. However, when faced with desiccation from a highly sorptive dust such as silica gel, lipid synthesis in cockroaches is too slow to keep up with the absorption that takes place. Large quantities of lipid are drawn from deep within the cuticle by highly sorptive dusts (Ebeling 1971).

Importance

Some cockroaches pose real threats to human health such as mechanically- spread surface pathogens. As an example, E. coli was the most common surface pathogen found on cockroaches by Vahabi et al. (2011) in Sanandaj city houses in Iran.

About 80% of the cockroaches tested were contaminated exteriorly with E. coli.

American cockroaches were contaminated more frequently than German cockroaches in this study.

Cockroaches can also serve as reservoirs and vectors of drug resistant

Salmonella. Devi and Murray (1991) found this to be the case after sampling cockroaches from hospitals, houses, animal sheds, grocery stores and restaurants in

South Kanara District, India, where 4.1% of these cockroaches (Blatta and Periplaneta species) harbored Salmonella. Additionally, a study conducted in Iran (Fathpour et al.

2003) found that American cockroaches were the most abundant species in hospitals, houses and poultry sheds, and that up to 70% of the roaches collected from hospitals harbored drug-resistant Salmonella. The authors also determined that Salmonella is

stable inside a cockroach for more than 10 months. American cockroaches have been found to carry Salmonella in the United States as well. Rueger and Olson (1969) sampled over 6,000 cockroach specimens found throughout 19 cities (all state capitals) and discovered a 1.24% natural infection rate.

Pai et al. (2005) found that American and German cockroaches collected from homes in Taiwan both harbored a total of 25 different species of bacteria on average.

American cockroaches were found in kitchens about 70% of the time. In an earlier study by Pai et al. (2003), about 37% of hospitals sampled in Taiwan had American cockroaches present and non-tuberculous mycobacteria were found on these roaches.

Besides harboring and spreading pathogens, cockroaches are also known to cause allergic reactions in sensitive people. Cockroach allergens are capable of sensitizing humans, which means that through exposure to these allergens, people can gain sensitivity and become allergic. These allergens are known to provoke constitutional (generalized) and local reactions (Bernton and Brown 1964).

According to Gelber et al. (1993), the primary sight of cockroach allergen accumulation in homes is in the kitchen. Cockroach allergens can also be found in bedroom carpet, bedding, and sofas. They found that about 20 to 40% of homes sampled in Delaware with no visible cockroaches present had detectable cockroach allergens in dust. Sources of cockroach allergen can include cockroach saliva, feces, secretions, cast skins, debris, and dead bodies.

Control

American cockroaches can be both domestic (Pope 1953) and peridomestic

(Fleet et al. 1978), being well adapted for living indoors and outdoors (Seelinger 1984).

American cockroaches are not found as often around homes in the US as Australian or

smokybrown cockroaches (Brenner 1988, Fleet et al. 1978), but their biology and control are similar. Mechanical exclusion is a critical part of controlling all peridomestic cockroaches. For example, because tree branches contacting roofs may allow for attic entry by smokybrown and American cockroaches (Hagenbuch et al. 1988), keeping branches trimmed away from contact with any roof can be an important part of pest management.

One of the most effective strategies for controlling peridomestic cockroaches is baiting on the outside of the structure so they do not come inside. As an example, 2.0%

Chlorpyrifos bait around a home was shown to be more effective than 0.04% chlorpyrifos spray solution applied to the exterior (Hagenbuch et al. 1988). Also, the combination of chlorpyrifos pellet bait and hydramethylnon gel bait was found to be more effective against Smokybrown cockroaches than a targeted spray of trelamethrin on the same species (Smith et al. 1997). Once peridomestic cockroaches are inside, treatment strategies must be reevaluated.

Domiciliary cockroaches can move in and out of hollow walls and can breed there in enormous numbers. The number of cockroaches in a wall void can be exacerbated by treatments outside of the wall with repellent insecticides (Ebeling 1978).

Treatment inside such voids with long-lasting residual insecticides would likely remedy the situation and prevent future infestations (Ebeling et al. 1969). Because cockroaches can be readily transported inside from outside locations, applying pesticides to wall and attic voids against cockroaches is not a guarantee of freedom from infestation. It should, however, decrease the need for treating inside living spaces against them (Ebeling

1978).

Of the many residual pesticides available today, pyrethroids generally have higher lethal toxicities than formulations that have been relied on historically such as carbamates or organophosphorous insecticides (Valles et al. 1999). With the advent of permethrin, the first photostable pyrethroid to show promise, interest of the agrochemical industry in pyrethroids was renewed (Soderlund and Bloomquist 1989).

Pyrethroids fall into two categories, or classes, depending on their action on sensory nerves (Gammon et al. 1981). Type I, or cyano-containing pyrethroids, elicit repetitive firing in these nerves after stimulation because of permanent binding to the voltage- gated sodium ion channels. Type II, or non-ciano-containing pyrethroids, cause bursts of spikes being fired off due to intermittent binding of the sodium ion channels. Type I and type II pyrethroids also produce different effects on sodium channel tail currents

(Soderlund and Bloomquist 1989). Cyano-containing pyrethroids inhibit Ca+Mg ATP hydrolysis in American cockroaches better than non-cyano-containing pyrethroids (Clark and Matsumura 1987).

Intermediates of type I and type II pyrethroids have intermediate effects, which supports the idea that one major physiological target is being affected. Primary target sites for types I and II are likely sodium ion channels. Because interruption of the neuroendocrine system, which is calcium-dependent, by low concentrations of pyrethroids has been implicated as one of the factors contributing to irreversible toxification, calcium ion channels could also be a minor target (Soderlund and

Bloomquist 1989). Though pyrethroids interact with several neurochemical processes, not all of these interactions are likely to be involved with disruption of nerve function

(Soderlund and Bloomquist 1989).

Because of the heavy use of pyrethroid insecticides, resistance to these chemicals is becoming more and more of a problem for some pest species (Potter et al.

2014). Within cockroaches, pesticide resistance is primarily known in the German cockroach, probably owing to a short lifecycle and heavy insecticide exposure, as compared to other cockroach species such as P. americana (WHO 1999). Because of the constant battle with insecticide resistance development, more and more pest control professionals may turn to desiccating dusts (Potter et al 2014). With the mode of action of sorptive dusts being mechanical, it is not likely that resistances will develop (Tarshis

1959, Potter et al. 2014). Additionally, though some conventional insecticides cause more rapid knockdown than desiccating dusts, death may not be as quickly accomplished by conventional treatments as by highly sorptive dusts (Ebeling and

Wagner 1961). A comparative study between 20 conventional insecticides and two silica gel desiccant dusts showed that these two dusts were superior in their overall insecticidal capabilities (Tarshis 1959).

Despite the benefits of desiccating dusts, their efficacy can be diminished under certain circumstances. For example, while desiccating dust residues are wet, the time required to affect 100% cockroach mortality increases, indicating a decrease in insecticidal efficacy. If dust residues become wet, extra time should be allowed for pest populations to decrease (Tarshis 1959). Stagnant air and humidity may also decrease sorptive dust efficacy (Ebeling and Wagner 1959). In the high moisture and humidity environment of a sewer system, microencapsulated chlorpyrifos spray provided one year of protection against American cockroaches whereas silica gel with synergized pyrethrins only provided one month of insecticidal activity (Rust et al. 1991).

The addition of ammonium fluorosilicate to silica gel does not increase speed of insect dehydration upon contact, but seems to be more effective than non-fluorinated silica under conditions of high humidity or available surface moisture. It is presumed that this increase in insecticidal efficacy is caused by the activation of fluoride because of the presence of available water (Ebeling 1971). If silica gel deposits are wet, the presence of fluoride in the silica is important for 100% mortality (Ebeling and Wagner

1959). This is likely due to silica particles not being available, being adhered to the substrate too tightly (Appel et al. 2004).

Fluorinated silica gels have an advantage over non-fluorinated silica products in that fluorination imparts to the particles a positive charge, which helps bind particles to insect cuticle. This advantage is lost, however, if fluorinated silica gel is exposed to open air for more than two or three months. Also, the same benefits obtained by adding ammonium fluorosilicate to silica gel are not seen against all arthropods (Ebeling 1971).

Ingestion of silica gel is not required for it to be effective. Insects need merely to crawl over a dusted surface, obtaining some of the dust on their cuticle for the dust to be effective (Tarshis 1959). Not all insects will be able to pick up lethal doses of silica gel when only thin deposits are left on surfaces. For example, cockroaches require their bodies, not just their feet, to contact the powder in order to obtain a lethal dose. When thicker deposits are required, using water as a carrier instead of applying a dry dust can be done. When water is used as a carrier, however, less of the dust deposit will be available to passing insects once dry because of caking. Solvents used as carriers allow for dust deposits that are more available to insects, but present possible explosion or health hazards (Ebeling and Wagner 1959).

Sorptive dusts have been shown over time to be more insecticidal than abrasive dusts (Ebeling and Wagner 1959). Diatomaceous earth is both abrasive and sorptive but is inferior to silica aerogels in their capacity to desiccate insects. As an example, grain-infesting beetles should be particularly susceptible to abrasive desiccants, but sorptive dusts still desiccate them more quickly (Ebeling 1971).

Field tests have been done using sorptive dusts against oriental, German, and brownbanded cockroaches, each with great success. No field tests have been done using sorptive dusts against American cockroaches, but lab tests indicate that treatments like those used against oriental cockroaches in the field should be as effective against American cockroaches (Tarshis 1959).

To test for improvement of efficacy of several toxicants, Ebeling and Wagner

(1961) mixed insecticides such as Dibrom, DDVP, malathion, parathion and Dylox into inert but sorptive dust diluents. It was discovered that these sorptive dusts as carriers did not always increase efficacy, and sometimes, decreased efficacy significantly.

Specifically, sorptive dusts decreased effectiveness of organophosporous toxicants, did not increase or decrease effectiveness of lindane and increased the effectiveness of

Sevin on German and brownbanded cockroaches. In a separate experiment, Ebeling

(1971) treated wood blocks with five chlorinated hydrocarbon insecticides in combination with three different sorptive dusts as carriers. He applied the same chlorinated hydrocarbon insecticides to other pieces of wood without dust carriers and hung all wood pieces in an attic for 17 months. After this time, only those wood pieces that were dusted had any effect on drywood termites (Incistermes minor). Additionally, it was discovered that the more sorptive the dust carrier, the faster the termites died.

Based on the literature reviewed herein, desiccant dusts can be used as carriers of toxicant pesticides to provide long-term insecticidal activity in wall voids. American cockroach populations should be controllable by limiting access to harborage, food and water, but when these are not feasible or possible, chemical treatments may be effective.

CHAPTER 3 LONGEVITY OF STARVED, WATER-DEPRIVED AMERICAN COCKROACHES IN WOOD HARBORAGES AT VARIOUS WOOD MOISTURE LEVELS

American cockroaches are considered pests due to their ability to mechanically vector pathogens (Rueger and Olsen 1969, Fathpour et al. 2003, Pai et al. 2005), cause allergic reactions (Bernton and Brown 1964, Gelber et al. 1993), and damage food and some household items including clothing and footwear (Takahashi 1924, Nigam 1933).

Preventing populations of these cockroaches from growing in and around homes is an important measure in protecting health and property. Being able to identify conditions conducive to infestation is critical to the success of a program aimed at controlling

American cockroach populations.

American cockroaches are peridomestic (Fleet et al. 1984), living and breeding in outdoor locations such as palm trees and decaying maple trees (Gould and Deay 1940), but will move inside when conditions outside may not be favorable (Pope 1953). Once inside, American cockroaches act as domestic cockroaches (Seelinger 1984), harboring in dark, damp and protected areas (Bell and Adiyodi 1981) such as wall voids, especially those that are moist (Owens and Bennett 1982, Benson 1987, Appel 1997).

While in wall voids, food and water sources for the cockroaches may be limited.

American cockroaches are known to consume paper (Nigam 1933, Wharton et al. 1965,

Gijzen et al. 1994), which is found on the back of drywall (Ferguson 2012). There are several cockroach species that are known to eat wood (Wharton et al. 1965, Scrivener et al. 1988, Klass et al. 2008). American cockroaches may also be able to eat wood or other wood products besides paper. It is important to find out how long American cockroaches may be able to live in wall voids and what factors help determine their

longevity, including dependence on wood moisture and their ability to consume cellulosic material.

The main goal of this study was to analyze the ability of American cockroaches to survive without food or water in wood harborages at various wood moisture levels.

Three research objectives addressed this goal: a) discover the relative humidity inside experimental units at 0, 5, 10, 15, 20, 25 and 30% wood moisture, b) discover optimum and suboptimum wood moisture levels for American cockroach survival at various life stages, and c) determine amounts of wood consumed by American cockroaches under these same test conditions through weighing fecal pellets composed of wood, post mortem.

Materials and Methods

Insects

American cockroach 1st-instar nymphs, 3rd-4th-instar nymphs and adults were collected from laboratory colonies for this study. All cockroaches had been maintained in the Urban Entomology laboratory located at the University of Florida in Gainesville,

Florida. Cultures of American cockroaches have been kept in colony at the University of

Florida since the 1950’s. The USDA originally provided these cockroaches. Laboratory colonies remained in the rearing room under the following controlled conditions: approximately 26oC, 55%RH and 12:12 h (L:D) photoperiod. Colonies were kept in large glass jars (25 cm height by 22.5 cm diameter) covered with a cloth lid secured by an elastic band. The cockroaches could seek refuge within various cardboard harborages, were fed dry dog food (Pedigree Puppy, Mars Inc., McLean, VA), and provided with water. Ultimate-instar nymphs were separated out into a jar where they were reared to adulthood under the conditions aforementioned. Adults used in this experiment were

drawn from this separate jar before reaching two weeks of age. Oothecae were also kept in a thrid jar under the conditions aforementioned from which 1st-instar nymphs were collected.

Harborages

Untreated white pine 2X4 studs (Home Depot Model # 161640) were cut to 9 X 9

X 3.8 cm with one 5.4 cm hole drilled to a depth of 1.5 cm in the center. Four 0.6-cm holes were drilled per block, one into each corner of the block, creating small wells into which water could be pipetted (Figure 3-1).

Prepared blocks were oven-dried at 104oC for 2 days, weighed, and then placed into Ziploc® quart-sized freezer bags to prevent uptake of atmospheric moisture. Using the pre-drilled wells, the blocks were wetted to 0, 5, 10, 15, 20, 25 or 30% wood moisture, relative to oven-dry, and left to allow uniform water absorption for four days in the plastic bag. The amount of water needed per block was determined using the formula: W=WDW x WM where W=needed water in grams, WDW= wood dry weight in grams and WM=% wood moisture desired. The seven wood moisture treatments were tested against the three life stage groups: 1st-instar, 3rd-4th-instar and adult. There were five replicates of each life stage group/treatment combination, making a total of

105 experimental units and 105 cockroaches used.

Bioassay

Cockroaches were anesthetized and then placed singly inside of the wetted wood block harborages using featherweight forceps. Adult cockroaches were sexed before placement into harborages. Pre-cut circles of acetate paper (3M Dual-Purpose

Transparency Film #CG5000) were placed over the harborages and secured with standard staples and an office stapler to prevent the cockroach from leaving the

harborage. The harborage unit was then secured in the plastic bag and weighed. To maintain constant wood moisture, this baseline weight was maintained weekly by the addition of water to the corner wells as needed throughout the duration of the experiment.

Adding water to the corner wells allowed for wood moisture to be kept near constant while preventing the water added from becoming directly available to the cockroach within the block. On a weekly basis, wood moisture was measured gravimetrically and water was added as needed to reestablish the baseline weight, thus maintaining the intended moisture level. Water added ranged from 0.9 g for 30-25% wood moisture blocks, to 0 g for 0-5% wood moisture blocks. No food or available water was provided inside the wood harborages. Relative humidity and temperature were measured by placing Onset® HOBO® Data Loggers (U10-003) into selected bags with the blocks and cockroaches (one data logger per moisture level per life stage). Mortality was assessed daily until all individuals were dead. Cockroaches were considered dead if unable to right themselves within 10 seconds after being flipped onto their dorsum.

After the death of the last cockroach, each block was removed from its bag and placed in an oven at 104oC for two weeks. After being removed from the oven, the acetate paper was removed and cockroach dry body weight and fecal pellet dry weight were measured using a Mettler-Toledo scale (Model MS105DU), and aluminum weigh boats (FisherbrandTM, Catalog No. 08-732-106). Fecal pellets were analyzed microscopically for wood content. Only fecal pellets composed of wood were included in the measurements (Figure 3-2).

Analysis

This experiment was a random block design. Three analyses of variance

(ANOVAs) were conducted to determine: 1) the effect of wood moisture content on longevity, in days, for each of three life stages (1st-instar nymphs, 3rd-4th-instar nymphs and adults) of the American cockroach, 2) the effect of cockroach longevity, while starved and water-deprived, on cockroach dry body weight at mortality, and 3) the effect of cockroach longevity on cockroach feces dry weight at mortality. Student’s T- tests were used to separate means as significant differences in outcomes were detected by the ANOVAs. The significance of the difference between male and female adult cockroach rate of wood consumption (feces weight at mortality/days lived) was determined using a t-test. Longevity data were log transformed and feces production per day data were square root transformed for analysis. P-values ≤ 0.05 were considered significant. All statistical analyses were completed using JMP® version

Results

Wood moisture had a significant impact on the longevity of 1st-instar nymphs

(F=62.8033; df=6; p<0.0001), 3rd-4th-instar nymphs (f=21.5101; df=6; p<0.0001) and adults (f=9.7070; df=6; p<0.0001) (fig. X). According to a connecting letters report for this data set, there were significant increases in longevity between the 5 and 20% wood moisture levels for 1st-instar nymphs. There was no significant increase in longevity from 20% to 30% wood moisture within the same age group. By the same report, there were significant increases in longevity between 0 and 15% wood moisture for both the

3rd-4th-instar nymphs and adults, but no significant increases in longevity between 15 and 30% wood moisture for these two age groups (Figure 3-3).

No 1st-instar nymphs were able to survive one full day with the 0% or 5% wood moisture treatments. The longest-lived cockroach for each life stage was in the 25% wood moisture treatment, at 25 days for 1st-instar nymphs, 104 days for 3rd-4th-instar nymphs and 53 days for adults. Except for the 0% wood moisture treatment, 3rd-4th- instar nymphs survived longer than 1st-instar nymphs or adults. The longevity trends of

1st-instar nymphs within 25 and 30% wood moisture treatments were very similar. The longevity trends of 3rd-4th-instar nymphs between 20 and 30% wood moisture treatments were similar and distinctly separated from the longevity trends of the four lower wood moisture treatments for the group. For the adults within the 15, 20 and 30% wood moisture treatments, 20% survivorship was reached within 21-24 days. Only the longevity of the 25% wood moisture group was consistently higher for the adults (Figure

3-4).

Wood moisture levels between 0 and 30% resulted in relative humidity values ranging from 15% to 98%. Wood moisture levels between 15 and 30% resulted in relative humidity levels >89% for all three cockroach life stages tested. Poor wood moisture (0%) resulted in all life stages dying in 1-2 days. For 1st-instar nymphs in 10 and 15% wood moisture treatments, or 72-89% relative humidity, the first cockroaches started dying by day 3. At the highest relative humidity levels (97.8-98%), 1st-instar nymphs began dying between days 9 and 15. Mortality of 3rd-4th-instar nymphs began between days 4 and 7 in the 42-73% relative humidity range, and between days 32 and

42 in the 96-98% relative humidity range. Adult cockroaches in the 47 to 77% relative humidity range started dying at day 4. At the 97% relative humidity level, adults began dying between 8 and 24 days (Table 3-1).

Dry body weight of cockroaches was lower for individuals that lived longer. This was significant for 3rd-4th-instar nymphs (f=27.61; df=1; p<0.0001) and adults (f=6.30; df=1; p=0.0172) but dry body weight of 1st-instar nymphs was not measured due to their extremely small size. Fecal weight also was not measured for 1st-instar nymphs due to no fecal material being found in their blocks. Longevity significantly affected the amount of wood fecal pellets produced for both 3rd-4th-instar nymphs (f=323.2171; df=1; p<0.0001) and adults (f=523.0593; df=1; p<0.0001) by mortality. Dallin visually observed a decrease in body mass of the 3rd-4th-instar nymphs and adults while fecal pellets composed of wood continued to be produced. As longevity increased, dry body weight at mortality tended to decrease for both 3rd-4th-instar nymphs and adults according to the line equations Y=61.96-0.4441*X and Y=199.1-2.466*X, respectively.

Conversely, as longevity increased, dry fecal weight at mortality tended to increase for both 3rd-4th-instar nymphs and adults according to the line equations

Y=0.706+0.2077*X and Y=6.569+0.4839*X, respectively (Figure 3-5). Between all wood moisture levels combined, adult male cockroaches produced significantly more fecal pellets composed of wood, while alive in their harborages, than did adult females

(t=2.49; df=1; p=0.0202), at a ratio of 2.3/1.

Discussion

For cockroaches that harbor in wood voids when food and water are not available, wood moisture is important for survival. In the present study, it was discovered that wood moisture positively influenced longevity of American cockroaches in wood voids. This result was not a direct consequence of wood moisture but rather relative humidity imparted by respective wood moisture levels. Other studies have looked at the effect of relative humidity on longevity of starved, water-deprived

cockroaches, but have not looked at the impact wood moisture has on longevity.

Termites depend on moisture in the wood they ingest for survival (McManamy et al.

2008). Some stored product pests are able to increase their body water content from ingesting grains with low moisture content (Bhattacharya et al. 2003, Benoit et al. 2005).

American cockroaches are not known to consume raw wood as a food source, but wood moisture is nevertheless key to their differential survival while deprived of food and drinking water.

Wood moisture had an effect on relative humidity within the experimental units used. Over the range of wood moisture levels used in this study (0-30%), corresponding changes in relative humidity were discovered. However, the stepwise change in wood moisture employed did not result in stepwise increases in relative humidity. Indeed, relative humidity resulting from wood moisture levels between 20 and 30% did not vary by more than about 3%. This was true for all three cockroach life stages tested.

However, relative humidity changed greatly through increasing wood moisture between

0% and 15%. The water in the white pine used for these wood harborages was continuously in flux with the air immediately around the blocks, following bidirectional diffusion, with all but the bottom faces of each block being available for evaporation.

Evaporation at the wood’s surface was directly responsible for the relative humidity next to the wood and within each bag (Droin et al. 1988).

1st-instar nymphs have an optimal and suboptimal relative humidity, which depends on wood moisture level. Dambach and Goehlen (1998) assessed the longevity of 1st-instar German cockroaches under various relative humidity levels in plastic containers and found that humidity played a key role in the survival of these

cockroaches when starved and deprived of water. They recorded 1st-instar German cockroaches living up to 9 days under 2% relative humidity and up to 11 days under

22.5% relative humidity. This contrasts sharply with the longevity of 1st-instar American cockroach nymphs in conditions of 15 to 41% relative humidity in the present experiment, which all lived less than one day. Additionally, 1st-instar German cockroach nymphs in the 1998 study lived up to 18 days at 50.5% relative humidity and more than

30 days at 75.5% relative humidity. None of the 1st-instar American cockroach nymphs in the present study lived beyond 25 days, even under 98% relative humidity. The disparity in longevity between American and German cockroach 1st-instar nymphs may be explained by the difference in cuticluar permeabilities between the species. Appel et al. (1983) measured the cuticular permeability of adult male German cockroaches to be about 20 μg/cm2/hr/mmHg and that of adult male American cockroaches to be about 54

μg/cm2/hr/mmHg. The authors suggest that cockroach species with lower cuticular permeability are better adapted to xeric environments than those with high cuticular permeability. American cockroaches are therefore less capable of withstanding desiccation than German cockroaches.

Relative humidity levels between 95 and 98% in the present study allowed 1st- instar American cockroach nymphs to live the longest. This range of relative humidity was provided by wood moisture contents between 20 and 30%, indicating this range to be optimal for the survival of 1st-instar nymphs. Wood moisture levels below this are suboptimal for their survival. The optimal relative humidity range for survival of the other life stages of the American cockroach may differ from that of the 1st-instar nymphs.

Tucker (1977) indicated that older cockroach nymphs could live longer than younger nymphs under food and water deprivation conditions due to lipid reserves in the fat body. The cockroach fat body has been likened to the vertebrate liver in function, though fat, glycogen and protein storage is it’s main purpose (Cameron 1961). These reserves are used for fuel and water under conditions of starvation and water deprivation. Tucker (1977) explained that older nymphs should have accumulated more lipid reserves than younger nymphs. It is possible, therefore, that 3rd-4th-instar nymphs of the American cockroach could be less susceptible to dehydration and starvation than

1st-instar nymphs. Results of this study indicate that this is indeed the case. For all wood moisture levels and accompanying humidity levels, 3rd-4th-instar nymphs lived longer than 1st instar nymphs.

Of the 35 nymphs in the 3rd-4th-instar range, five were observed to have molted within the first week of being placed into their harborages. These were within the 5, 10 and 15% wood moisture treatment groups. It is possible that individuals in the higher wood moisture groups also shed, but consumed the complete exuvium. With all instances of shedding taking place within a matter of six to seven days following placement in blocks, it is possible that the nymphs that molted were close to molting before being isolated. Starvation and water deprivation arrested the development of the nymphs.

While cockroach nymphs will molt until adulthood, adult cockroaches do not continue to molt. The development time of American cockroach nymphs varies with several environmental conditions, but can take almost two years in total, with anywhere from 6 to 13 molts occurring during the process. Adult female American cockroaches

can live over three years. Under normal conditions, the adult stage lasts longer on average than any of the nymphal stages (Bell and Adiyodi 1981). Under suboptimal conditions, adult cockroaches may not live longer than nymphal stages. While starved and water-deprived in the present study, adult cockroaches lived longer than 3rd-4th- instar nymphs under 17-47% relative humidity. However, relative humidity levels between 77 and about 98% allowed 3rd-4th-instar nymphs to live longer than adults under the same starvation and water-deprivation conditions. The difference in longevity may be due to uric acid and urate salts replacing lipid reserves in the fat body (Tucker

1977, Park et al. 2013). No significant difference in longevity was found for the adults between 15 and 30% wood moisture levels, or 90 to 98% relative humidity. This suggests that this high range of wood moisture and accompanying relative humidity is optimal for the survival of adult American cockroaches.

While provided with food and water, cockroaches will produce fecal material as a part of the digestive process. Without food, feces production should cease. The cockroaches in this study were denied food and available drinking water, yet were observed to be producing fecal pellets throughout the experiment, with the exception of

1st-instar nymphs. These pellets were analyzed microscopically and discovered to be composed of wood fragments. By association, it is clear that the 3rd-4th-instar nymphs and adults were consuming wood. The 1st-instar nymphs may have failed to consume wood due to a lack of cellulose-digesting endosymbionts, which would necessarily be acquired through coprophagy (Cruden and Markovetz 1984, Watanabe and Tokuda

2010) and they were never exposed to older cockroaches (see Materials and Methods).

Alternatively, the wood available could have been too difficult for very small nymphs to

bite through, though no work has been done to ascertain the bite force of young cockroaches (Weihmann et al. 2015).

The 3rd-4th-instar nymphs and adults in this study were chewing wood and ingesting it instead of leaving chewed fragments behind. Carpenter ants are known to chew wood for the sake of excavating galleries, but this activity does not involve the ingestion of wood. The wood particles removed are discarded instead because wood is not part of a carpenter ant’s diet (Suiter 2009). Similarly, wood is not known to be a nutritive food item for American cockroaches (Scrivener et al. 1998).

The cockroaches chewing the wood in which they harbored could be an attempt to escape. If this were the case, leaving the chewed wood fragments behind, could be expected. However, cockroaches are known to chew and ingest several items that may be considered non-food including clothes, boots, paper, hair, books (Nigam 1933) and wire insulation (Appel 1995). No work has been done on the ingestion of raw wood by

American cockroaches.

It is known that American cockroaches possess enzymes necessary to break down cellulose. Some argue these cellulases are endogenous (Wharton et al. 1965,

Slaytor 1992, Genta et al. 2003). The well-developed foregut and midgut of the

American cockroach could indicate that cellulose digestion takes place via endogenous cellulases, however, the species does not have a hindgut as well developed as

Panesthia spp. (wood feeders), indicating that these enzymes for cellulose degradation could be endogenous (Watanabe and Tokuda 2009).

Regardless of potential cellulase sources, cockroaches in this study lost more body weight before death the longer they lived, indicating that the cockroaches were not

able to convert the cellulose from the wood they consumed into enough useable energy, if any at all (Figure 3-5). Gijzen et al. (1994) conclude that, based on endogenous

FPase (an enzyme that degrades filter paper) activity in the hind gut of P. americana, adults of this species could digest about 2 mg of cellulose per day. White pine, as used for harborages in this experiment, contains approximately 60% cellulose (Mahood and

Cable 1922). Dividing the dry weight of wood fecal pellets by the number of days lived in the wood harborages, it is evident that the cockroaches in this study consumed on average just less than 2 mg of cellulose per day. It is unknown if this amount of cellulose digestion would be sufficient for daily nutritional needs.

If cockroaches consume sufficient nutritive material, it is expected that their body weight will be at least maintained. Throughout the test period, adult and 3rd-4th-instar nymphs continuously lost weight the longer they lived, despite consuming wood from their harborages continuously. The fecal pellets produced from the consumption of wood appeared to contain whole, undigested fragments of chewed wood (Figure 3-2).

Wharton et al. (1965b) showed that adult female American cockroaches chewed filter paper, especially before producing oothecae, and that some of the paper ended up shredded on the floor of the cage while much of it was ingested. This took place despite available Purina Laboratory Chow, chicken eggs and carrots. Even though adult males were never observed chewing the filter paper, they excreted more cellulase in their feces than the adult females. In the present study, males were found to produce more wood fecal pellets than females relative to the amount of time they lived in their wood harborages, indicating that males ate wood more readily than females (Figure 3-6). It is important to note that while the cockroaches in this study were deprived of food and

water, the cockroaches in the Wharton et al. (1965b) study were not. There are likely different reasons for each sex of the adult American cockroach to chew wood or paper, though it is not possible to discuss with certainty any reasons within the context of this research, indicating a need for additional research on the subject.

Relative humidity as determined by wood moisture level in a harborage is important for cockroach survival. This study identified wood moisture levels that are optimum and suboptimum for American cockroach survival at various life stages. It was also discovered that the longer the cockroaches could survive without alternative food sources in a wood void, the more wood they would consume. At higher wood moisture levels, cockroaches could live longer and consume more wood. According to the results of this work, American cockroach population increase would not be likely inside of a wood harborage, such as a wall void, when wood moisture is below 15%. Importantly, this wood moisture level is within the range conducive to termite infestation (12-20%). It is recommended that wood moisture levels in walls be kept below this range for the sake of termite management (BASF 2004, Orkin 2017), therefore appropriate low wood moisture levels in wall voids will help in the management of both termites and cockroaches.

Table 3-1. Days to mortality for starved and water-deprived 1st-instar nymphs, 3rd-4th- instar nymphs and adult American cockroaches at 0-30% wood moisture and resulting relative humidities. Days to Mortality % Wood % Relative Range Median Moisture Humidity+SE 1st-instar Nymphs 0 15.0+0.9 1* 1 5 41.5+1.1 1* 1 10 72.8+1.1 3-14 3 15 89.0+1.6 3-8 7 20 95.3+0.9 10-15 13 25 97.8+1.2 9-25 18 30 98.0+1.9 15-24 16 3rd-4th-instar Nymphs 0 15.1+0.9 2-6 6 5 42.2+1.3 4-30 6 10 73.1+1.1 7-40 30 15 89.3+1.7 27-56 39 20 96.0+1.4 41-89 57 25 97.9+1.0 32-104 63 30 98.1+1.9 42-93 71 Adults 0 17.7+2.9 2-9 4 5 47.0+1.8 4-17 14 10 77.5+1.3 4-36 17 15 90.3+1.3 17-32 22 20 96.7+1.4 15-27 21 25 97.0+1.4 24-53 29 30 97.8+1.9 8-38 22 *All individuals died within the first day.

Harborage

Well

Figure 3-1. Wood block harborage with acetate paper circle stapled over the top and a 1st-instar nymph inside. Four holes were used as wells for increasing wood moisture. Photo by Dallin Ashby

Standard Diet White Pine

Figure 3-2. Fecal pellets of an adult American cockroach, derived from standard cockroach diet (left) and white pine (collected from the wood harborage in which it lived while deprived of food and water. Fecal pellets composed of wood were much lighter in color than pellets derived from standard cockroach diet. They also contained visible wood fragments throughout. Photo by Dallin Ashby.

Figure 3-3. Mean longevity in days of 1st-instar nymphs (A), 3rd-4th-instar nymphs (B) and adults (C) of American cockroaches living in wood harborages at different moisture levels. Means within each life stage group followed by the same letter are not significantly different (p<0.05, Student’s T-test, JMP 12.1.0, 2015).

Figure 3-4. Longevity of 1st-instar nymphs (A), 3rd-4th-instar nymphs (B), and adults (C) of the American cockroach while starved and water-deprived in wood harborages of various wood moisture levels.

Y=61.96-0.4441*X R2=0.456

Y=0.706+0.2077*X R2=0.486

Y=199.1-2.466*X R2=0.391

Y=6.569+0.4839*X R2=0.152

Figure 3-5. Linear fit of fecal pellet (composed of wood) and body weights, post mortem, of starved and water-deprived 3rd-4th-instar nymphs (A) and adults (B) of the American cockroach.

0.42

0.18

Figure 3-6. Mean weight of wood-composed fecal pellets (feces weight at mortality/days lived) produced by starved, water-deprived male (M) and female (F) American cockroaches (t=2.49, p=0.0202, t-test, JMP version 12.1.0, 2015).

CHAPTER 4 EFFICACY OF POSSIBLE PRECONSTRUCTION WALL VOID TREATMENTS AGAINST AMERICAN COCKROACHES, SILVERFISH AND FLORIDA CARPENTER ANTS

The ability of American cockroaches to access and infest wall voids has been established (Owens and Bennett 1982). Other insects are also known to infest wall voids, including carpenter ants and silverfish. Florida carpenter ants can access wall voids during active foraging (Ebeling et al. 1969) and nests can be found inside of wall voids (Fowler 1986). Though carpenter ants do not consume the wood in which they harbor, they can nevertheless exacerbate damage already done by fungus or other insects (Warner and Scheffrahn 2002). Silverfish may access wall voids, seeking shelter

(Ebeling et al. 1969) and potentially food, feeding on the paper (Morita 1926) on the drywall that is exposed within wall voids of wood frame structures (Ferguson 2012).

Also, an association of an unknown species of silverfish with Florida carpenter ants has been documented (Davis and Jouvenaz 1990).

Appel (1997) suggested that cockroach wall void infestations are avoidable by making such harborages unsuitable for habitation. The author also pointed out that post-construction treatments, such as foam applications to wall voids, can be expensive and may not be cost-effective. Preconstruction treatments against wall void infestations should ideally remain effective for up to five years, equal to the requirements in place for preconstruction termiticide treatments (Florida Bureau of Entomology and Pest Control

2013). Ebeling et al. (1967) indicated that dusting wall voids could lead to long-term control due to the inert nature of desiccant dusts. The application of desiccant dusts as spray formulations during building construction is possible, though studies indicate that

knockdown of cockroaches might take more time after exposure to a dust that has been applied wet vs. a dust that was applied dry (Tarshis 1959).

With wood being a common building material in wall voids (Understand Building

Construction 2017), and American cockroaches, silverfish and Florida carpenter ants being known to infest wall voids, the present study aimed to test the efficacy of potential pre-construction treatments to wood-framed houses against these insects. Three research objectives in two experiments addressed this goal: a) determine the relative efficacy of Arilon®, Phantom®, TalstarOne™, and Totality™ applied as a spray to wood, either as stand-alone treatments or in combination with CimeXa™ against silverfish,

Florida carpenter ants and/or American cockroaches, b) determine the effect of the addition of CimeXa™ on the longevity of Arilon®, Phantom®, TalstarOne™, and

Totality™, and c) discover differential effects of the treatments listed on the three species listed.

Materials and Methods

Insects

American cockroach 3rd-4th-instar nymphs were collected from laboratory colonies for two independent studies as described throughout this chapter. All cockroaches had been maintained in the Urban Entomology laboratory located at the

University of Florida in Gainesville, Florida. Cultures of American cockroaches have been kept in colony at the University of Florida since the 1950’s. The USDA originally provided these cockroaches. Laboratory colonies remained in the rearing room under the following controlled conditions: approximately 26oC, 55%RH and 12:12 h (L:D) photoperiod. Colonies were kept in large glass jars (25 cm height by 22.5 cm diameter) covered with a cloth lid secured by an elastic band. The cockroaches could seek refuge

within various cardboard harborages, were fed dry dog food (Pedigree(R) Puppy, Mars

Inc., McLean, VA), and provided with water.

Silverfish (Lepisma saccharina) were collected from lab-raised colonies. Colonies have been maintained in the Urban Entomology laboratory located at the University of

Florida in Gainesville, Florida, under controlled conditions: approximately 26oC, 55% RH and 12:12 h (L:D) photoperiod. Stock cultures originally obtained from the USDA have been replenished multiple times since the 1950’s with individuals collected within the laboratory storage room. Silverfish were reared in clear SteriliteTM totes (part number

18468010) measuring approximately 59 cm long x 43 cm wide x 16 cm deep with white lids. The sides of the totes were lined with petroleum jelly, on the inside and outside, to prevent escape as well as entrance by ants or other insects. The entire bottom of each tote was lined with paper towels to provide traction. Flat pieces of cardboard of various dimensions were stacked from 12 to 15 pieces high in the middle of each tote. Tongue depressors were used within the highest half of the cardboard stack to provide space between individual pieces of cardboard. About 12 cardboard tubes of various lengths, with diameters ranging from 1.5 to 4 cm, were also provided as harborage along the lengths of the totes. Food consisted of chicken pellets and egg noodle dry pasta, though paper and cardboard consumption was common. Chicken pellets (Purina Layena

Pellets, Purina Animal Nutrition LLC, Shoreview, MN) were offered whole and ground.

Similarly, egg noodle pasta (Publix® wide egg noodle pasta, Publix Asset Management

Company, Lakeland, FL) was offered in fragments sieved to size #12 or ground. Dry food was placed on paper towels one teaspoon per food type in each end of the tote, making two teaspoons of each food type placed every two weeks. Water was provided

by placing two water-filled vials with cotton stoppers into each tote. Water was only provided between December and May of each year to prevent excess moisture within the totes during summers. Small and mid-sized individuals were not taken for this experiment, only large individuals. Silverfish were harvested by tapping parts of their cardboard harborages over plastic deli cups so that forceps were not needed.

Florida Carpenter Ants (Camponotus floridanus) were collected from lab-raised colonies that had been maintained at the University of Florida in the Urban Entomology laboratory since July of 2015. The colony was maintained in plastic bins (Panel Controls

Corp., Detroit, MI) (41 cm long x 38 cm wide x 11.5 cm high) lined with Fluon® (BioQiop

Products, Rancho Dominguez, CA). Cells used for harborages were made of plastic

Petri dishes interiorly lined with dental stone (Castone, DENTSPLY International Inc.,

York, PA) and topped with red cellophane to reduce light intensity. The ants were provided the three major macronutirents, lipids, proteins, and carbohydrates, in various food sources. Once a week, food trays were refilled with fruit, eggs, jelly, honey and dead insects, which typically comprised of cockroaches or crickets reared on site. Ants were also supplied both tap and sugar water and were maintained at approximately

25oC, 50% RH, and on a 12:12 H (L:D) cycle. Ants were harvested for use in this experiment with featherweight forceps to reduce potential harm to the insects.

Wood Blocks

Wood blocks were created using untreated white pine “1X4” furring strip boards

(Home Depot model# 687642). These were cut to the dimensions of 9-cm by 9-cm by

1.8-cm each. Sixty-milliliter deli cups (Dart Conex clear portion containers, stock number 400PC, Dart Corp., Mason, MI) were used to contain the insects on the treated wood surfaces. Deli cups were secured in place by rubber bands. The cups for the

surface treatment experiment (Arilon®, Phantom®, TalstarOne™ alone and in combination with CimeXa™) received a single centrifuge tube (part number 3440,

Thermo ScientificTM, Waltham, MA), with the cap removed, filled with water and stoppered with cotton, and adhered to the inside edge of the cup with hot glue (Figure

4-1). The cups for the wood treatment experiment (Totality™ alone and in combination with CimeXa™) were not supplied with water.

Treatments

Surface treatment experiment. The following chemicals were used in this experiment: CimeXa™, 100% amorphous silica (Rockwell Labs Ltd., Kansas City, MO),

Phantom® Termiticide-Insecticide, 21.45% Chlorfenapyr (BASF Corporation, Research

Triangle Park, NC), DuPont™ Arilon® Insecticide, 20% Indoxacarb (E. I. du Pont de

Nemours and Company, Wilmington, DE), and TalstarOne™, 7.9% Bifenthrin (FMC

Corporation, Philadelphia PA). Arilon®, Phantom®, and TalstarOne™ are each broad- spectrum insecticides. The pesticide label for Arilon® includes cockroaches and ants

(broadly) as target organisms. The labels for Phantom® and TalstarOne™ include

American cockroaches, carpenter ants and silverfish as target organisms. The pesticide label for CimeXa™ includes ants, cockroaches and silverfish (broadly).

Wood treatment experiment. CimeXa™ and Totality™ Wood Treatment, 23.4%

Bifenthrin (FMC Corporation, Philadelphia, PA) were tested in the wood treatment experiment. Totality™ is labeled only for treatment of wood against wood-destroying organisms.

Formulations. Of the treatments used in experiments 1 and 2, four were pesticide mixtures, combining CimeXa™ with the four toxicants: Arilon®, Phantom®,

TalstarOne™ (surface treatment experiment), and Totality™ (the wood treatment

experiment). These four toxicants were also diluted alone to act as four stand-alone treatments in the same respective experiments. A ninth treatment was CimeXa™ alone, which was used in both experiments. The control used in both experiments was distilled water. Formula concentration rates were as follows. CimeXa™ was mixed per the label rate of 1.438 g of powder into 12 mL of water. Totality™ was mixed at the label rate of

0.03 mL of concentrate into 11.97 mL of water. TalstarOne™ was mixed at the high label rate of 0.05 mL into 12 mL of water. Phantom® was mixed at the high label rate of

0.29 mL into 12 mL of water. Arilon® was mixed at the high label rate of 59 mg into 12 mL of water. Combinations of toxicants and CimeXa™ were created by mixing specified concentrates into a single 12-mL volume of water.

An airbrush (Paasche H#3 airbrush with A-1/8-6 hose, Paasche Airbrush

Company, Chicago, IL), set to 25 PSI, was used to apply each treatment to one face of the prepared wood blocks at the rate of 0.35-mL/M2, which is the point of surface saturation.

Accelerated Aging

In experiments 1 and 2, treatments on wood blocks were artificially aged using the oven heating method described by the EPA (2012) wherein two weeks in an oven at

54oC + 2oC was equivalent to one year of chemical degradation. This protocol was based on the Arrhenius equation, k=Ae-Ea/RT where k is the constant representing the rate of reaction, T is the absolute temperature in Kelvins under which the reaction occurs, A is the prefactor, Ea is the activation energy, and R is the universal gas constant (Laidler 1984). All treated blocks to be artificially aged were placed in an oven together, while those to be used at one day post treatment were kept out. Blocks were placed into the oven the same day as treatments were applied to them. Those to be

used for testing 1 year of chemical degradation remained in the oven for 2 weeks.

Similarly, those to be used for testing 2 years of chemical degradation remained in the oven for 4 weeks, and those to be used for testing 5 years of degradation remained in the oven for 10 weeks. Therefore, accelerated aging times were 0 days (used at day 1, without placement in the oven), 2 weeks, 4 weeks and 10 weeks.

Bioassays

Surface treatment experiment. American cockroach 3rd-4th-instar nymphs, silverfish and Florida carpenter ant majors were subjected to all seven treatments and the control after the four accelerated aging times just described had been accomplished. Mortality was assessed at 24 hours, 48 hours and 7 days after the initiation of exposure. Three replicates of each treatment were used against each insect type with five insects per rep, for a total of 96 experimental units and 480 each of cockroaches, silverfish and carpenter ants, between all four accelerated aging times.

Wood treatment experiment. American cockroach 3rd-4th-instar nymphs were subjected to all three treatments and the control after the four accelerated aging times had been accomplished. Mortality was assessed at 24 hours. Five replicates were used per treatment, with five cockroaches in each replicate for a total of 80 experimental units and 400 cockroaches used between all four accelerated aging times.

For both experiments, mortality was defined as the inability of the insects to hold on to the wood surface upon which they rested when oriented upside-down.

Analysis

Both the surface treatment and wood treatment experiments were random block design. Some mortality occurred in the control groups in the surface treatment experiment, therefore mortality rates were corrected using Abbott’s formula (Abbott

1925). To compare the efficacy of the treatments in the surface treatment experiment

(Arilon®, Phantom®, and TalstarOne™ alone or with CimeXa™), within each accelerated aging time, an ANOVA was conducted per accelerated aging time with %mortality as the dependent variable and treatment as the independent variable. Student’s T-tests were used to separate the means (Figure 4-2). To determine the efficacy of Totality™ and/or CimeXa™ against American cockroach 3rd-4th-instar nymphs in the wood treatment experiment, a 2-way ANOVA was conducted for each treatment with

%mortality as the dependent variable and ‘CimeXa™ or Not’ (whether CimeXa™ was part of the treatment or not) and accelerated aging time as the independent variables.

Where significant differences were indicated, Student’s T-tests were used to identify significance between levels (Figure 4-3). To determine the effects of Phantom®,

TalstarOne™, and Arilon® with or without CimeXa™ on the mortality rates of American cockroaches, silverfish and Florida carpenter ants, a 2-way ANOVA was conducted for each insect species involved and each toxicant combination, with %mortality as the dependent variable and ‘CimeXa™ or Not’ (whether CimeXa™ was part of the treatment or not) and accelerated aging time as the independent variables. Student’s T- tests were used to identify significant differences between levels (Figures 4-4, 4-5, and

Results

In the surface treatment experiment, percent mortality in the control groups varied by insect and amount of accelerated aging as follows. For 0 days of accelerated aging, 40%, 33.3% and 6.7% of carpenter ants, cockroaches and silverfish respectively had died during the experiment. For 2 weeks of accelerated aging, 66.6%, 0% and 0%

of carpenter ants, cockroaches and silverfish respectively had died during the experiment. For 4 weeks of accelerated aging, 80%, 6.7% and 0% of carpenter ants, cockroaches and silverfish respectively had died during the experiment. For 10 weeks of accelerated aging, 73.3%, 0% and 6.7% of carpenter ants, cockroaches and silverfish respectively died during the experiment.

Mortality rates between treatments in the surface treatment experiment were significantly different for 0 days (f=4.5019; df=6; p=0.0004), 2 weeks (f=5.0964; df=6; p=0.0001), 4 weeks (f=14.7196; df=6; p<0.0001), and 10 weeks (f=25.5069; df=6; p<0.0001) of accelerated aging. Student’s T-tests separated the means of the mortality rates as shown in Figure 4-2. Mortality rates in the wood treatment experiment were not significantly different between treatments at 0 days accelerated aging (f=2.250; df=2; p=0.1480), but were significantly different at 2 weeks (f=576.0; df=2; p<0.0001), 4 weeks (f=121.0; df=2; p<0.0001) and10 weeks (f=35.6296; df=2; p<0.0001) of accelerated aging. The efficacy of CimeXa™ alone in the wood treatment experiment was significantly different across all four accelerated aging times (f=4.1143; df=3; p=0.0243). See Figure 4-3 for separation of means. For the surface treatment experiment, significant differences in mortality rates between treatments were found within Florida carpenter ants (f=5.8350; df=6; p<0.0001), American cockroaches

(f=27.9137; df=6; p<0.0001), and silverfish (f=15.4433; df=6; p<0.0001). Accelerated aging had a significant impact on treatments in experiments 1 (f=4.9757; df=18; p=<0.0001) and 2 (f=27.8963; df=9; p=<0.0001). The difference in mortality rates between Totality™ mixed with CimeXa™ and CimeXa™ alone were not significantly different (t=-1.551; df=76; p=0.1251) over the four accelerated aging times in the wood

treatment experiment. Interactions were discovered in the surface treatment experiment between accelerated aging time and treatment (f=14.2735; df=6; p<0.0001) as well as insect and treatment (f=7.9492; df=12; p<0.0001). No interaction was found between accelerated aging time and insect (f=2.6822; df=2; p=0.0696).

Discussion

Insecticide treatments to wood frame members of walls can remain effective for about five years, providing protection against some common insects that are known to infest wall voids. Various insecticide formulation treatments do not have the same levels of efficacy either one day after application or over the equivalent of several years post application, depending on formulation. This is especially true relative to the presence or absence of amorphous silica gel in the formulation. Of the insecticides tested in this study, most retained significantly longer efficacy when mixed with CimeXa™.

Ebeling (1971) found that five chlorinated hydrocarbon insecticides applied to wooden blocks had longer-lasting insecticidal effects (aged in an attic for 17 months) on drywood termites when the pesticides had been diluted in various dusts as compared to those not diluted in dusts. It was also found that the more sorptive the dust diluent was, the more insecticidal the residue was. In the present study, the highly desiccant dust, amorphous silica gel (CimeXa™) was found to provide a similar effect on pesticide longevity when in combination with pesticides in use today, namely Arilon®, Phantom®, and TalstarOne™.

Arilon®, Phantom® and TalstarOne™ are broad-spectrum insecticides with multiple pest species indicated on their respective labels. With their differing formulations, including active ingredients (BASF 2017, DuPont 2017, FMC 2017a), mortality rates of various insects were expected to be different across the artificial aging

intervals tested. Indeed, Phantom® and TalstarOne™ both decreased in efficacy over accelerated aging intervals while Arilon® maintained its insecticidal capacity. With the addition of CimeXa™ to these three insecticides, efficacy did not diminish significantly over the four aging intervals. With Totality™ being a wood treatment-specific pesticide

(FMC 2017), the efficacy of this treatment may differ from that of broad-spectrum insecticides when also applied to wood.

Totality™ provided 100% mortality of American cockroach 3rd-4th-instar nymphs after 24 hours of exposure to the one-day-old residue. Mortality rates for this formulation were never above 25% after just two weeks in the oven (one year of accelerated aging).

However, combining CimeXa™ with Totality™ provided 100% mortality over the remaining aging intervals tested in this study.

Differences in insecticide efficacy also existed between the insect species tested.

More Florida carpenter ants died in the control groups than the other two insects. Only one insecticide (Phantom®) caused mortality rates significantly lower than 100% for the species. Regardless of treatment, most ants were dead by day two of each sampling interval. In contrast, American cockroaches and silverfish shared similar trends in mortality rates, with Phantom® and TalstarOne™ both decreasing significantly in efficacy against these insects over accelerated aging.

The mean mortality rate for CimeXa™ alone against American cockroaches and silverfish in the surface treatment experiment never reached greater than 80%, whereas the mortality rate against Florida carpenter ants reached 100% consistently across aging intervals. Faulde et al. (2006) found that total population eradication of American cockroaches (50 nymphs and 50 adults) could be achieved in eight days, even with food

and water available, when the insects were exposed to a hydrophobised diatomaceous earth (addition of 1,1,1-trimethyl-N-trimethylsilane), which is composed primarily of silica. Similarly, complete population (100 adults) eradication of silverfish was accomplished in nine days with the same treatment.

While the American cockroach nymphs exposed to CimeXa™ alone in the surface treatment experiment never suffered mortality rates above 80%, those nymphs in the wood treatment experiment exposed to CimeXa™ alone experienced mortality rates as high as 100%. This disparity may be explained by the lack of available water in the wood treatment experiment whereas those in the surface treatment experiment had drinking water available (see Materials and Methods).

The combination of CimeXa™ with Arilon® or Talstar™ caused about 100% mortality for all three insect species tested across all aging intervals. These two broad- spectrum formulations could be considered as candidates for preconstruction treatments against wall void infestation by American cockroaches, silverfish and Florida carpenter ants. The combination of CimeXa™ and Totality™ caused 100% mortality against American cockroach nymphs. Though Totality™ is a wood treatment-specific insecticide, this combination could also be a candidate as a preconstruction treatment for wall studs against cockroaches and potentially other insects. Whether or not the addition of CimeXa™ affected the penetrability into wood of any of the insecticides tested was not discerned. However, the presence of CimeXa™ on the wood’s surface apparently allowed some of the toxicants mixed with it to stay available on the surface, as evidenced by the decrease in efficacy over time of toxicants not mixed with

CimeXa™ but no decrease in efficacy over time when mixed with CimeXa™. Further

testing should be done to determine the effect of the combination on wood-destroying organisms, as these are the targeted organisms on the Totality™ label. These three treatments, Arilon®, Talstar™ and Totality™, when mixed with CimeXa™, could provide protection for about five years. It is important to note that all pesticide applications and mixtures should be accomplished in accordance with label restrictions and state and federal laws.

Figure 4-1. Experimental unit used to test the efficacy of insecticide treatments on wood against cockroaches, silverfish and carpenter ants. A 60-mL deli cup was secured to the treated surface of white pine with elastic bands. Photo by Dallin Ashby.

A B

C D

Figure 4-2. Abbott’s corrected mortality rates of 3rd-4th-instar American cockroaches, silverfish and Florida carpenter ants combined, after seven days of exposure to seven pesticide treatments on wood: CimeXa™, Ar+Ci (Arilon® with CimeXa™), Arilon®, Ph+Ci (Phantom® with CimeXa™), Phantom®, Ta+Ci (TalstarOne™ with CimeXa™), and TalstarOne™. Exposure to treatments took place after 0 days (A), 2 weeks (B), 4 weeks (C) and 10 weeks (D) of accelerated aging in an oven. Bars within each graph not sharing letters were significantly different.

Figure 4-3. Mortality rates of 3rd-4th-instar American cockroaches after 24 hours of exposure to CimeXa™ (A), Totality™, or a combination of Totality™ and CimeXa™ (B), at 0 days, 2 weeks, 4 weeks and 10 weeks of accelerated aging in an oven. Bar pairs not sharing letters were significantly different.

A B

C D

Figure 4-4. Abbott’s corrected mortality rates of 3rd-4th-instar American cockroaches after 7 days of exposure to CimeXa™ alone (A), Arilon® (B), Phantom® (C), or TalstarOne™ (D) at 0 days, 2 weeks, 4 weeks and 10 weeks of accelerated aging in an oven. Pairs of bars not sharing letters were significantly different. Graphs without letters had no significant differences.

A B

C D

Figure 4-5. Abbott’s corrected mortality rates of silverfish after 7 days of exposure to CimeXa™ alone (A), CimeXa™ mixed with: Arilon® (B), Phantom® (C), or TalstarOne™ (D), at 0 days, 2 weeks, 4 weeks and 10 weeks of accelerated aging in an oven. Pairs of bars not sharing letters were significantly different. Graphs without letters had no significant differences.

A B

C D

Figure 4-6. Abbott’s corrected mortality rates of Florida carpenter ants after 7 days of exposure to CimeXa™ alone (A), CimeXa™ mixed with: Arilon® (B), Phantom® (C), or TalstarOne™ (D), at 0 days, 2 weeks, 4 weeks and 10 weeks of accelerated aging in an oven. Pairs of bars not sharing letters were significantly different. Graphs without letters had no significant differences.

CHAPTER 5 CONCLUSIONS

This is the first study to measure the longevity of starved, water-deprived

American cockroaches in wood harborages and specifically measure the longevity of

1st-instar nymphs of the species under these conditions. Longevity was found to be correlated with wood moisture content and the resulting relative humidity levels. The highest three wood moisture levels (20-30%) produced nearly equivalent relative humidity levels. As expected, those cockroaches in blocks at higher wood moisture levels and consequently higher relative humidity survived the longest. It is apparent that atmospheric moisture is an important determining factor for the longevity of American cockroaches while starved and water-deprived.

Controlling the moisture levels inside of wall voids should allow for limitation of wall void infestations by cockroaches. Specifically, relative humidity levels less than

15% will not allow water-deprived 1st-instar nymphs and adults of the American cockroach to live beyond about two weeks. Mid-instar nymphs may live 50 or more days under 15% relative humidity when water-deprived. Feeding on celluslosic material by

American cockroaches will also therefore decrease with lower wood moisture and consequent relative humidity.

Both 3rd-4th-instar nymphs and adults consumed some of the wood in which they were kept during this research. After comparing dry wood fecal pellets produced during the experiment to the longevity of the cockroaches as well as dry body weight at mortality, it was determined that the consumption of wood did not allow these otherwise starving cockroaches to thrive under the aforementioned conditions. Therefore, though

wood-feeding activity may be prolonged by high wood moisture in a wall void, the feeding will not sustain individuals or populations.

Willis and Lewis (1957) found that when cockroaches were provided food but not water, they only lived as longs as those that had no food or water. Further testing should be done to determine if cockroaches under the same conditions as in this study, which ate wood but failed to thrive, could have thrived (i.e. molt through successive life stages) if water were provided. This is of special consideration given the amount of cellulose that Gijzen et al. (1994) calculated could be digested per day by an American cockroach, though the cellulose in that study was in the form of paper, not raw wood as in the present study.

The wood used in both the longevity study at various wood moistures and the preconstruction treatment efficacy study was white pine, though cut to different dimensions. This wood was chosen because of its common use as wall framing material

(NELMA 2005). In a wall void, cockroaches and other insects may be able to take advantage of warm, humid conditions for harborage, especially if there are structural problems associated that cause excessive moisture (Benson 1987). Wood in these wall voids is a major moisture sink, allowing relative humidity to stay somewhat stable (Droin et al. 1988).

Inasmuch as wall void humidity may not always be controllable within suboptimal levels for cockroach survival, pesticide applications to wall void members should be considered. The application of desiccant dusts to wall frame members could help prevent infestation of wall voids by cockroaches and other insects (Ebeling et al. 1969).

The present body of work has shown that wood treated with the desiccant dust

CimeXa™ can kill three different insects known to infest wall voids, even when provided with water, though mortality rates never exceeded 80% after seven days of exposure in two of three insects. Phantom®, TalstarOne™ and Totality™ alone lost efficacy over time, but when mixed with CimeXa™, their efficacy was maintained over at least five years, never dropping significantly below 100% mortality. It is possible that this is due to residues of the toxicants staying on the wood’s surface with the CimeXa™ acting as a matrix. It is also possible that CimeXa™ increases an insect’s susceptibility to the toxicants, causing prolonged efficacy, though these two possible causes are not mutually exclusive.

In an experiment by Ebeling et al. (1966), German cockroaches avoided mock wall voids that were treated with silica gel, but not mock wall voids treated with boric acid. Cockroaches can be repelled by desiccant dusts, which could limit the amount of exposure they have to toxicants, but the repellency of desiccant dusts could fulfill the role of making a wall void uninhabitable by insects, even if the interactions of CimeXa™ and toxicants are mutually exclusive.

The concept behind using Totality™ as a termiticide is that the treatment will penetrate the wood’s surface (up to 6 mm) and remain available for attacking termites for at least six years (FMC 2017). When CimeXa™ and Totality™ are combined, it is not certain that enough of the Totality™ will penetrate the wood to act as a termiticide while the remainder stays on the wood’s surface to act as a broad-spectrum insecticide.

Further research should be done to determine any effect CimeXa™ might have on the usability of Totality™ as a termiticide.

Of the toxicants tested in this research, only Totality™ is currently labeled as a termiticide that can be applied to wood framing. Therein lies the advantage of mixing

Totality™ with CimeXa™. The Totality™ /CimeXa™ combination was shown to be highly effective against American cockroaches, even after five years of accelerated aging. With Totality™ already suitable for treatment of wood framing, the addition of

CimeXa™ to preconstruction treatments with it would help save resources, as post construction wall void treatments should be unnecessary within at least the first five years.

Though the other pesticides tested (Arilon®, Phantom® and TalstarOne™) are not currently labeled for use as termiticides applied to wood framing, the concept of tank mixing with CimeXa™ for improved longevity remains the same for at least Phantom® and TalstarOne™ . The label for Arilon® indicates that it is not to be used for long-term control of termites, but its efficacy remained high against the three insects on the wood’s surface in this study, even without the incorporation of CimeXa™.

LIST OF REFERENCES

Abbot, W. S. 1925. A method for computing the effectiveness of an insecticide. J. Econ. Entomol. 18: 265-267.

Anon. 2002. Plant protection products. Ministry of Agriculture, General Directorate of Protection and Control, Istanbul, Turkey.

Appel, A. G. 1995. Blattella and related species, pp. 1-19. In M. K. Rust, J. M. Owens, and D. A. Reierson [eds.] Understanding and controlling the German cockroach. Oxford University Press, Inc., New York, NY.

Appel, A. G. 1997. Nonchemical appes to cockroach control. J. Agric. Entomol. 14: 271-280.

Appel, A. G., M. J. Gehret, and M. J. Tanley. 2004. Effects of moisture on the toxicity of inorganic and organic insecticidal dust formulations to German cockroaches (Blattodea: Blattelidae). J. Econ. Entomol. 97: 1009-1016.

Appel, A. G., D. A. Reierson and M. K. Rust. 1983. Comparative water relations and temperature sensitivity of cockroaches. Comp. Biochem. Physiol. 74: 357-361.

Appel, A. G., and M. K. Rust. 1985. Water distribution and loss in response to acclimation at constant humidity in the smokybrown cockroach, Periplaneta fuliginosa (Serville). Comp. Biochem. Physiol. 80A: 377-380.

Appel, A. G., and L. M. Smith II. 1999. Perception and repellency of moving air by American and smokybrown cockroaches (Dictyoptera: Blattidae). J. Econ. Entomol. 92: 170-175.

Arruda, L. K., V. P. L. Ferriani, L. D. Vailes, A. Pomes, and M. D. Chapman. 2001. Cockroach allergens: Environmental distribution and relationship to disease. Current allergy and asthma Reports 1:466-473.

Asahina, S. 1961. A revised list of the Japanese cockroaches of sanitary importance (Insecta, Blattaria). Jap. J. M. Sc. & Biol. 14: 147-156.

Ballard, J. B., H. J. Ball, and R. E. Gold. Influence of selected environmental factors upon German cockroach (Orthoptera: Blattellidae) exploratory behavior in choice boxes. J. Econ. Entomol. 77: 1206-1210.

Bandi, C., M. Sironi, G. Damiani, L Magrassi, C. A. Nalepa, U. Laudani, and L. Sacchi. 1995. The establishment of intracellular symbiosis in an ancestor of cockroaches and termites. Proc. R. Soc. Lond. B. 259: 293-299.

Barbara, K. A. 2014. American cockroach: Periplaneta americana (Linnaeus)(Insecta: Blattodea: Blattidae). http://entomology.ifas.ufl.edu/creatures/urban/roaches/american_cockroach.htm Accessed January 6, 2017.

BASF. 2004. Subterranean termites: detection and control. Prescription Treatment® brand pest management bulletin. 8: 1.

BASF. 2017. Phantom termiticide insecticide specimen label. http://www.cdms.net/ldat/ld5M2014.pdf. Accessed June 30, 2017.

Bell, W. J., and K. G. Adiyodi. 1981. The American cockroach. Chapman and Hall Ltd., New York, NY.

Benoit, J. B., J. A. Yoder, E. J. Rellinger, J. T. Ark, and G. D. Keeney. 2005. Prolonged maintenance of water balance by adult females of the American spider beetle, Mezium affine Boieldieu, in the absence of food and water resources. J. Insect Physiol. 51: 565-573.

Benson, E. P. 1987. Harborage preference by Periplaneta americana (L.) and Periplaneta fuliginosa (Serville) (Dicty- optera: Blattidae) in a home in Clemson, South Carolina. J. Entomol. Sci. 22: 39–44

Bernton, H. S., and H. Brown. Insect allergy: preliminary studies of the cockroach. J. Allergy 35: 506-513.

Bhattacharya, B., A. Barik, and T. C. Banerjee. 2003. Bioenergetics and water balance in Callosobruchus maculatus (F.) (Coleoptera: Bruchidae) larval populations. Oriental Insects 37: 423-437.

Bignell, D. E. 1977. An experimental study of cellulose and hemicellulose degradation in the alimentary canal of the American cockroach. Can. J. Zool. 55: 579-589.

Bryan, E. H. 1926. Insects of Hawaii, Johnston Island and Wake Island. Bull. Bernice P. Bishop Mus. 31: 1-94.

Buczkowski, G., C. W. Scherer, and G. W. Bennett. 2008. Horizontal transfer of bait in the German cockroach: Indoxacarb causes secondary and tertiary mortality. J. Econ. Entomol. 101: 894-901.

Cameron, E. 1961. The cockroach (Periplaneta americana, L.): an introduction to entomology for students of science and medicine. Heinemann, Portsmouth, NH.

Carpenter, F. M., and L. Burnham. 1985. The geological record of insects. Ann. Rev. Earth Planet. Sci. 13: 297-314.

Clark, J. M., and F. Matsumura. 1986. The action of two classes of pyrethroids on the inhibition of brain Na-Ca and Ca+Mg ATP hydrolyzing activities of the American cockroach. Comp. Biochem. Physiol. C. 86:135-145.

Cruden, D. L., and A. J. Markovetz. 1984. Microbial aspects of the cockroach hindgut. Arch. Microbiol. 138: 131-139.

Dambach, M., and B. Goehlen. 1999. Aggregation density and longevity correlate with humidity in first-instar nymphs of the cockroach (Blattella germanica L., Dictyoptera). J. Ins. Physiol. 45: 423-429.

Davis, L. R., and D. P. Jouvenaz. 1990. Obeza floridana, a parasitoid of Camponotus abdominalis floridanus from Florida (Hymenoptera: Eucharitidae, Formicidae). Fla. Entomol. 73: 335-337.

Devi, S. J. N., and C. J. Murray. 1991. Cockroaches (Blatta and Periplaneta species) as reservoirs of drug-resistant salmonellas. Epidemiol. Infect. 107: 357-361.

Droin, A., J. L. Taverdet, and J. M. Vergnaud. 1988. Modeling the kinetics of moisture adsorption by wood. Wood Sci. Technol. 22: 11-20.

DuPont. 2017. http://www.dupont.com/content/dam/assets/products-and-services/pro- products/SL-1672C.pdf. Accessed June 30, 2017.

Ebeling, W. 1971. Sorptive dusts for pest control. Annu. Rev. Entomol. 16:123-158.

Ebeling, W. 1978. Past, present and future directions in the management of structure infesting insects, pp. 221-247. In G. W. Frankie, C. S., Koehler [eds.], Perspectives in Urban Entomology. Academic Press, Inc., New York, NY.

Ebeling, W., and R. J. Pence. 1956. UCLA entomologists evaluate research data on drywood, subterranean termite control. Pest Control 24: 46, 50, 52, 54-58, 62, 64.

Ebeling, W., D. A. Reirson, and R. E. Wagner. 1967. Influence of repellency on the efficacy of blatticides, II: laboratory experiments with German cockroaches. J. Econ. Entom. 60: 1375-1390.

Ebeling, W., and R. E. Wagner. 1959. Rapid desiccation of drywood termites with inert sorptive dusts and other substances. J. Econ. Entom. 52: 190-207.

Ebeling, W., and R. E. Wagner. 1961. Relation of lipid adsorptivity of powders to their suitability as insecticide diluents. Hilgardia 30: 565-586.

Ebeling, W., R. E. Wagner, and D. A. Reirson. 1969. Insect-proofing during building construction. Calif. Agr. 23: 4-7.

Fathpour, H., G. Emtiazi, and E. Ghasemi. 2003. Cockroaches as reservoirs and vectors of drug resistant salmonella spp. Iran. Biomed. J. 7:35-38.

Faulde, M. K., J. J. Scharninghausen, S. Cavaljuga. 2006. Toxic and behavioural effects of different modified diatomaceous earths on the German cockroach Blattella germanica (L.) (Orthoptera: Blattellidae) under simulated field conditions. J. Stored Prod. Res. 42: 253-263.

Faulde, M. K., M. Tisch, and J. J. Scharninghausen. 2006. Efficacy of modified diatomaceous earth on different cockroach species (Orthoptera, Blattellidae) and silverfish. J. Pest. Sci. 79: 155-161.

Ferguson, M. R. 2012. Drywall, 4th edition. The Taunton Press, Inc., Newtown, CT.

Fleet, R. R., G. L. Piper, and G. W. Frankie. 1978. Studies on the population ecology of the smokybrown cockroach, Periplaneta fuliginosa, in a Texas Outdoor Urban Environment. Environ. Entomol. 7: 807-814.

Florida Bureau of Entomology and Pest Control. 2013. What you need to know about subterranean termites, home construction and liability, pp. 158-160. In P. G. Koehler, E. A. Buss, W. H. Kern Jr., R. M. Pereira, and R. W. Baldwin [eds.], Pests in and around the southern home. University of Florida, Institute of Food and Agricultural Sciences, Gainesville, FL.

FMC. 2017a. TalstarOne™ multi-insecticide. http://www.fmcprosolutions.com/Portals/pest/Content/Docs/Labels/Talstar%20P %20Professional%2004-17-13R%20Comm.pdf. Accessed 6-30-17.

FMC. 2017b. Totality™ wood treatment. http://www.fmcprosolutions.com/PestControl/Products/InsecticidesTermiticides/ TotalityWoodTreatment.aspx. Accessed 5-20-17.

Gammon, D. W., M. A. Brown, and J. E. Casida. 1981. Two classes of pyrethroid action in the cockroach. Pestic. Biochem. Physiol. 15: 181-191.

Gelber, L. E., L. H. Seltzer, J. K. Bouzoukis, S. M. Pollart, M. D. Chapman, and T. A. E. Platts-Mills. 1993. Sensitization and exposure to indoor allergens as risk factors for asthma among patients presenting to hospital. Am. Rev. Respir. Dis. 147: 573 578.

Genta, F. A., W. R. Terra, C. Ferreira. 2003. Action pattern, specificity, lytic activities, and physiological role of digestive beta-glucanases isolated from Periplaneta americana. Ins. Biochem. Mol. Biol. 33: 1085

Gould, G. E., and H. O. Deay. 1938. The biology of the American cockroach. Ann. Entomol. Soc. Am. 31: 489-498.

Gould, G. E., and H. O. Deay. 1940. The biology of six species of cockroaches which inhabit buildings. Purdue Univ. Agric. Exp. St. Bull. 451: 2-31.

Grace, K. J., and R. T. Yamamoto. 1994. Simulation of remedial borate treatments intended to reduce attack on Douglas-fir lumber by the formosan subterranean termite (Isoptera: Rhinotermitidae). J. Econ. Entomol. 87: 1547-1554.

Grandcolas, P. 1998. Domestic and non-domestic cockroaches: Facts versus received ideas. Rev. Fr. Allegrol. 38(10): 833-838.

Hagenbuch, B. E., P. G. Koehler, R. S. Patterson, and Richard J. Brenner. 1988. Peridomestic cockroaches (Orthoptera: Blattidae) of Florida: their species composition and suppression. J. Med. Entomol. 25: 377-380.

Haines, T. W., and E. C. Palmer. 1955. Studies of distribution and habitat of cockroaches in Southeastern Georgia, 1952-53. Am. J. Trop. Med. Hyg. 4: 1131 1134.

Hougard, J.-M., S. Duchon, M. Zaim, and P. Guillet. Bifenthrin: a useful pyrethroid insecticide for treatment of mosquito nets. J. Med. Entomol. 39: 526-533.

Inward, D., G. Beccaloni, and P. Eggleton. 2007. Death of an order: a comprehensive molecular phylogenetic study confirms that termites are eusocial cockroaches. Biol. Lett. 3: 331-335.

Jones, S. C. 2008. Agriculture and natural resources; American cockroach. http://ohioline.osu.edu/hyg-fact/2000/pdf/2096.pdf. Accessed February 15, 2017.

Kaakeh, W., B. L. Reid, and G. W. Bennett. 1997. Toxicity of fipronil to German and American cockroaches. Entomol. Exp. Appl. 84: 229-237.

Klass, K.-D., C. Nalepa, and N. Lo. 2008. Wood-feeding cockroaches as models for termite evolution (Insecta: Dictyoptera): Cryptocercus vs. Parasphaeria boleiriana. Mol. Phylogenet. Evol. 46: 809-817.

Koehler, P. G., B. E. Bayer, and D. Branscome. 2011. Cockroaches and their management, pp. 119-124. In P. G. Koehler, E. A. Buss, W. H. Kern, Jr., and R. M. Pereira [eds.], Pests in and around the Florida home. University of Florida, Institute of Food and Agricultural Sciences, Gainesville, FL.

Laidler, K. J. 1984. The development of the Arrhenius equation. J. Chem. Educ. 61: 494.

Lee, C. Y., and L. C. Lee. 2000. Influence of sanitary conditions on the field performance of chlorpyrifos-based baits against Ameican cockroaches, Periplaneta americana (L.) (Dictypotera: Blattidae). J. Vect. Ecol. 25: 218-221.

Legendre, F., A. Nel, G. J. Svenson, T. Robillard, R. Pellens, and P. Grandcolas. 2015. Phylogeny of Dictyoptera: Dating the origin of cockroaches, praying mantises and termites with molecular data and controlled fossil evidence. PLoS ONE 10: e0130127. doi:10.1371/journal.pone.0130127.

Leoncini, I., and C. Rivault. 2005. Could species segregation be a consequence of aggregarion processes? Example of Periplaneta americana (L) and P. fuliginosa (Serville). Ethology 111: 527-540.

Lilly, D. G., C. E. Webb, and S. L. Doggett. 2016. Evidence of tolerance to silica baesd desiccant dusts in a pyrethroid-resistant strain of Cimex lectularius (Hemiptera: Cimicidae). Insects 7: 74. Lo, N., G. Tokuda, H. Watanabe, H. Rose, M. Slaytor, K. Maekawa, C. Bandi, and H. Noda. 2000. Evidence from multiple gene sequences indicated that termites evolved from wood-feeding cockroaches. Current Biology 10: 801-804.

Maketon, M., A. Hominchan, and D. Hotaka. 2010. Control of American cockroach (Periplaneta americana) and German cockroach (Blattella germanica) by entomopathogenic nematodes. Rev. Col. Entomol. 36: 249-253.

Melton, R. H. 1995. Differential adaptation to water deprivation in first-instar nymphs of the German cockroach (Blattella germanica) and the brown-banded cockroach (Supella longipalpa). Entomologia Experimentalis et Applicata. 77: 61-68.

Miller, D. M., F. Meek. 2004. Cost and efficacy of integrated pest management strategies with monthly spray of insecticide applications for German cockroach (Dictyoptera: Blattellidae) control in public housing. J. Econ. Entomol. 97: 559 569.

Morita, H. 1926. Some observations on the “silverfish” (Lepisma saccharina L.) (Thys.). Proc. Haw. Ent. Soc., 6: 271-273.

National Research Council. 1980. Urban Pest Management. Rep. Comm. Urban Pest Manage. Environ. Stud. Board, Comm. Nat. Resourc. Washington, DC: Nat. Accad. Press.

(NELMA) Northeastern Lumber Manufacturer’s Association. 2005. Eastern white pine information and resources. http://www.nelma.org/library/eastern-white-pine- product-resources/. Accessed 7-17-17

Ngoh, S. P., L. E. W. Choo, F. Y. Pang, Y. Huang, M. R. Kini, and S. H. Ho. 1998. Insecticidal and repellent properties of nine volatile constituents of essential oils

against the American cockroach, Periplaneta americana (L.). Pestic. Sci. 54: 261-268.

Nigam, L. N. 1933. The life-history of a common cockroach (Periplaneta Americana Linneus). Ind. J. Agric. Sci. 3, 530-543.

Olkowski, W. 1974. A model ecosystem management program. Proc. Tall Timbers Conf. Ecol. Anim. Cont. Habitat Manage. 5:103-117.

Orkin. 2017. Termite moisture meters. https://www.termites.com/treatment/inspections/termite-moisture-meters/ Accessed 6-22-17.

Oswalt, D. A., A. G. Appel, and L. M. Smith II. 1997. Water loss and desiccation tolerance of German cockroaches (Dictyoptera: Blattellidae) exposed to moving air. Comp. Biochem. Physiol. 117A: 477-489.

Owens, J. M. and G. W. Bennett. 1982. German cockroach movement within and between urban apartments. J. Econ. Entomol. 75: 570-573.

Pai, H. H., W. C. Chen, and C. F. Peng. 2003. Isolation of non-tuerculous mycobacteria from hospital cockroaches (Periplaneta americana). J. Hosp. Infect. 53: 224-228.

Pai, H. H., W. C. Chen, and C. F. Peng. 2005. Isolation of bacteria with antibiotic resistance from household cockroaches (Periplaneta americana and Blattella germanica). J. Acta Tropica 93: 259-265.

Pope, P., 1953. Studies of the life histories of some Queensland Blattidae (Orthopter). Part 1, The domestic species. Proc. Row. Soc. Qd. 63: 23-46.

Potter, M.F., K. F. Haynes, J. R. Gordon, L. Washburn, M. Washburn, and T. Hardin. 2014. Silica gel: a better bed bug desiccant. Pest Control Technol., 42, pp.78-94.

Rau, P. 1940. The life history of the American cockroach, Periplaneta americana. Ent. News. 51: 273.

Reynierse, J. H., A. Manning, and D. Cafferty. 1972. The effects of hunger and thirst on body weight and activity in the cockroach (Nauphoeta cinerea). J. Anim. Behav. 20: 751-757.

Rueger M. E., and T. A. Olson. 1969. Cockroaches (Blattaria) as vectors of food poisoning and food infection organisms. J. Med. Ent. 6(2): 185-189.

Rust, M. K., D. A. Rierson, and K. H. Hansgen. 1991. Control of American cockroaches (Dictyoptera: Blattidae) in sewers. J. Med. Entomol. 28: 210-213.

Schal, C., and R. L. Hamilton. 1990. Integrated suppression of synanthropic cockroaches. Annu. Rev. Entomol. 35: 521-551.

Scrivener, A. M., H. Watanabe, and H. Noda. 1998. Properties of digestive carbohydrase activities secreted by two cockroaches, Panesthia cribrata and Periplaneta americana. Comp. Biochem. Physiol. 119B: 273-282.

Seelinger, G. 1984. Sex-specific activity patterns in Periplaneta americana and their relation to mate-finding. Z. Tierpsycol. 65: 309-326.

Seelinger, G., and B. Schuderer. 1985. Release of male courtship display in Periplaneta americana: evidence for female contact sex pheromone. Anim. Behav. 33: 599-607.

Slaytor, M. 1992. Cellulose digestion in termites and cockroaches: what roll do symbionts play? Comp. Biochem. Physiol. 103: 775-784.

Smith, L. M., and A. G. Appel. 1996. Toxicity, repellence, and effects of starvation compared among insecticidal baits in the laboratory for control of American and smokybrown cockroaches (Dictyoptera: Blattidae). J. Econ. Entomol. 89: 402 410.

Smith, L. M., A. G. Appel, T. P. Mack, G. J. Keever, and E. P. Benson. 1997. Evaluation of methods of insecticide application for control of smokybrown cockroaches (Dictyoptera: Blattidae). J. Econ. Entomol. 90: 1232-1242.

Smith, L. M., A. G. Appel, T. P. Mack, and G. J. Keever. 1999. Preferred temperature and relative humidity of males of two sympatric Periplaneta cockroaches (Blattoea: Blattidae) denied access to water. Environ. Entomol. 28: 935-942.

Soderlund, D. M., and J. R. Bloomquist. 1989. Neurotoxic actions of pyrethroid insecticides. Ann. Rev. Entomol. 34: 77-96.

Solomon, J., M. B. Sandler, M. A. Cocchia, and A. Lawrence. Effect of environmental illumination on nymphal development, maturation rate, and longevity of Periplaneta americana. Ann. Entomol. Soc. Amer. 70: 409-413.

Sriwichai, P., D. Nacapunchai, S. Pasuralertsakul, Y. Rongsriyam, and U. Thavara. 2002. Survey of indoor cockroaches in some dwellings in Bangkok. Southeast Asian J. Trop. Med. Public Health. 33: 36-40.

Suiter, D. R. 2009. Biology and management of carpenter ants. http://extension.uga.edu/publications/detail.cfm?number=B1225. Accessed 6-22 17.

Takahashi, R. 1924. Life-history of Blattidae. Dobutsugaku Sasshi, Zool. Mag. Tokyo 36, 215-230.

Tarshis, I. 1959. Sorptive dusts on cockroaches: easily applied compounds harmless to animals and humans effectively control cockroaches and other household pests. Calif. Agr. 13:3-5.

Triplehorn, C. A., and N. F. Johnson. 2005. Borror and Delong’s introduction to the study of insects. Brooks/Cole, Belmont, CA.

Understand Building Construction. 2017. Timber frame construction. http://www.understandconstruction.com/wood-framed-construction.html. Accessed March 6, 2017.

UNEP. 2008. Stockholm Convention. http://chm.pops.int/TheConvention/ThePOPs/AllPOPs/tabid/2509/Default.aspx. Accessed May 23, 2017.

Vahabi, A., K. Shemshad, P. Mohammadi, M. Sayyadi, M. Shemshad, and J. Rafinejad. 2011. Microbiological study of domestic cockroaches in human dwelling localities. Afr. J. Microbiol. Res. 5: 5790-5792.

Valles, S. M., P. G. Koehler, and R. J. Brenner. 1999. Comparative insecticide susceptibility and detoxification enzyme activities among pestiferous Blattodea. Comp. Biochem. Phys. C. 124: 227-232.

Wall, B. J. 1970. Effects of dehydration and rehydration on Periplaneta americana. J. Insect Physiol. 16: 1027-1042.

Wagner, R. E., and W. Ebeling. 1959. Lethality of inert dust materials to Kalotermes minor Hagen and their role as preventives in structural pest control. J. Econ. Entomol. 52: 208-212.

Wang, C., and G. W. Bennett. 2006. Comparative study of integrated pest management and baiting for German cockroach management in public housing. J. Econ. Entomol. 99: 879-885.

Warner, J. and R. H. Scheffrahn. 2002. Florida carpenter ant, Camponotus floridanus (Buckley). http://entnemdept.ufl.edu/creatures/urban/ants/fl_carpenter_ants.htm. Accessed July 11, 2017.

Watanabe, H., and G. Tokuda. 2010. Cellulolytic systems in insects. Annu. Rev. Entomol. 55: 609-632.

Wharton, D. R. A., M. L. Wharton, and J. Lola. 1965a. Blood volume and water content of the male American cockroach, Periplaneta americana L.: methods and the influence of age and starvation. J. Ins. Physiol. 11: 391-404.

Wharton, D. R. A., M. L. Wharton, and J. Lola. 1965b. Cellulase in the cockroach, with special reference to Periplaneta americana (L.). J. Ins. Physiol. 11: 947-959.

Willis, E. R., and N. Lewis. 1957. The longevity of starved cockroaches. J. Econ. Entomol. 50: 438-440.

Zaim, M., A. Aitio, and N. Nakashima. 2000. Safety of pyrethroid-treated nets. Med. Vet. Entomol. 14: 1-5.

BIOGRAPHICAL SKETCH

Dallin Myles Ashby is the fourth of six children born to Warren and Nancy Ashby.

He was born and raised in Woods Cross, Utah, where he graduated from Woods Cross

High School in 2001. Shortly after graduating from high school, Dallin served a two-year mission for his church to the people of the Philippine islands. Upon returning home,

Dallin married and began his own family, and then graduated from Salt Lake

Community College with an Associate of Science degree in biology. After earning a

Bachelor of Science degree in biology from the University of Utah, Dallin worked in the pest control industry as a pest control operator in Salt Lake City for about four years.

Looking for new opportunities and growth, he brought his family to the University of

Florida to work on his Master of Science degree in entomology and nematology under the direction of Drs. Philip Koehler, Rebecca Baldwin and Roberto Pereira. While studying at the University of Florida, Dallin served as president of the Urban

Entomological Society for one year, was awarded the 2016 Insect IQ scholarship and wrote an article for PestPro magazine on occasional invaders. Upon graduation from the University of Florida, Dallin immediately re-entered the pest management industry to fulfill his life’s ambitions.